Evaluation of rTMS in patients with poststroke aphasia: a systematic review and focused meta-analysis

Effects of speech rehabilitation training combined with repetitive transcranial magnetic stimulation on patients with post-stroke aphasia

OBJECTIVE

The study focused on effects of speech rehabilitation training combined with repetitive transcranial magnetic stimulation (rTMS) in patients with post-stroke aphasia (PSA).

METHODS

Ninety-six patients with PSA were divided into two groups. One group received speech rehabilitation training (ST group, n = 48) and one group received speech rehabilitation training combined with rTMS treatment (ST + rTMS group, n = 48), both of which were treated continuously for 4 weeks. The post-treatment effects of the two groups and the Boston Diagnostic Aphasia Examination (BDAE), Chinese Rehabilitation Research Center Standard Aphasia Examination (CRRCAE), Communicative Ability in Daily Life (CADL), Stroop Color and Word Test (SCWT), Montreal Cognitive Assessment (MoCA), and Barthel Index (BI) scores before and after treatment were compared in both groups.

RESULTS

After treatment, the total effective rate of the ST + rTMS group was higher than that of the ST group (p < 0.05). Both groups exhibited improved BDAE grade; CRRCAE, CADL, SCWT, MoCA, and BI scores increased in both groups, and were higher in the ST + rTMS group than in the ST group (all p < 0.05).

CONCLUSION

Speech rehabilitation training combined with rTMS can effectively improve speech function in PSA, with remarkable rehabilitation effects.

Semantic and Phonological Abilities Inform Efficacy of Transcranial Magnetic Stimulation on Sustained Aphasia Treatment Outcomes

A growing body of evidence has shown that repetitive transcranial magnetic stimulation (rTMS) can enhance word-retrieval abilities in chronic aphasia. However, there remains significant variability in the efficacy of combined rTMS and language treatments. This study investigated how semantic and phonological characteristics of baseline word-retrieval impairments may influence the efficacy of rTMS on long-term naming improvements following language treatment in individuals with chronic aphasia. Thirty participants with post-stroke aphasia underwent 10 sessions of 1 Hz rTMS to right pars triangularis followed by a modified constraint-induced language treatment (mCILT). Nineteen participants were randomly assigned to active rTMS and 11 participants were assigned to sham rTMS. All participants completed the Philadelphia Naming Test (PNT) at baseline and at 3 and 6 months post-treatment. We coded PNT errors and fit data to the semantic-phonological (or SP) computational model (Foygel & Dell, 2000) to derive semantic and phonological parameter weights. We ran linear regressions for the proportional improvement in naming, with fixed effects for interactions between rTMS, time, and baseline parameter weights. While there was no immediate effect of rTMS post-treatment, rTMS combined with mCILT improved long-term naming more than language therapy alone. Furthermore, greater baseline semantic and phonological characteristics of word-retrieval abilities were each associated with increased rTMS-induced gains in proportional naming improvements. These patterns were maintained at both 3 and 6 months post-treatment. This study is among the first in a larger sample to demonstrate that individual differences in lexical retrieval contribute to variability in sustained rTMS and aphasia treatment outcomes.

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

Introduction

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

Materials and methods

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

Results

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

Conclusion

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

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

Background

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

Objective

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

Method

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

Results

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

Conclusion

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

The Therapeutic Effect of Transcranial Magnetic Stimulation on Post-stroke Aphasia and the Optimal Treatment Parameters: A Meta-analysis

OBJECTIVE

This meta-analysis aimed to examine the overall effectiveness of TMS on post-stroke aphasia using a meta-analysis approach, as well as examine the effect of moderating variables (eg, study design, TMS protocol) on the effectiveness of TMS.

DATA SOURCES

A keyword search was conducted in 5 databases: ERIC, Google Scholar, PsycINFO, MEDLINE, and ProQuest (01/1985-12/2022). The search algorithm included all possible combinations of relevant keywords. Full-text articles were thoroughly examined using forward/backward search methods.

STUDY SELECTION

Studies were thoroughly screened using the following inclusion criteria: patients were diagnosed with post-stroke aphasia; studies focused on the effect of TMS on post-stroke aphasia; language assessments were conducted at pretest and posttest for TMS treatment and data were reported; studies included both an experimental group (ie, a group with TMS treatment) and a control group (ie, a group without TMS treatment).

DATA EXTRACTION

Information was extracted from each study including authors, publication year, first language of participants, study design, stroke duration, demographics of participants, TMS protocol, stimulation site, targeting, and statistical data of language performance pre- and post-TMS treatment.

DATA SYNTHESIS

A total of 17 studies were included in the final review, involving 682 patients with post-stroke aphasia (348 in the experimental group, 334 in the control group). The results showed that TMS treatment has significant immediate (Hedges' g=0.37) and maintenance (Hedges' g=0.34) effects on post-stroke aphasia. Additionally, the moderating variables showed a moderation effect on the effectiveness of TMS.

CONCLUSION

TMS treatment can significantly improve language ability for post-stroke aphasia. Additionally, this study provides an important reference for selecting the optimal TMS treatment parameters in treating post-stroke aphasia. Specifically, administering 15 sessions of rTMS lasting 10 min over the mirror area within Broca's area may produce the best TMS treatment outcomes.

Neuropsychological and Anatomical-Functional Effects of Transcranial Magnetic Stimulation in Post-Stroke Patients with Cognitive Impairment and Aphasia: A Systematic Review

Transcranial magnetic stimulation (TMS) has been found to be promising in the neurorehabilitation of post-stroke patients. Aphasia and cognitive impairment (CI) are prevalent post-stroke; however, there is still a lack of consensus about the characteristics of interventions based on TMS and its neuropsychological and anatomical-functional benefits. Therefore, studies that contribute to creating TMS protocols for these neurological conditions are necessary. To analyze the evidence of the neuropsychological and anatomical-functional TMS effects in post-stroke patients with CI and aphasia and determine the characteristics of the most used TMS in research practice. The present study followed the PRISMA guidelines and included articles from PubMed, Scopus, Web of Science, ScienceDirect, and EMBASE databases, published between January 2010 and March 2023. In the 15 articles reviewed, it was found that attention, memory, executive function, language comprehension, naming, and verbal fluency (semantic and phonological) are the neuropsychological domains that improved post-TMS. Moreover, TMS in aphasia and post-stroke CI contribute to greater frontal activation (in the inferior frontal gyrus, pars triangularis, and opercularis). Temporoparietal effects were also found. The observed effects occur when TMS is implemented in repetitive modality, at a frequency of 1 Hz, in sessions of 30 min, and that last more than 2 weeks in duration. The use of TMS contributes to the neurorehabilitation process in post-stroke patients with CI and aphasia. However, it is still necessary to standardize future intervention protocols based on accurate TMS characteristics.

Repetitive transcranial magnetic stimulation for post-stroke non-fluent aphasia: a systematic review and meta-analysis of randomized controlled trials

Objective

To systematically evaluate the efficacy and safety of repetitive transcranial magnetic stimulation (rTMS) on language function in patients with non-fluent aphasia post-stroke.

Methods

We selected randomized clinical trials (RCT) that involved stroke patients with non-fluent aphasia, whose intervention was rTMS vs. no therapy or other therapy. Two researchers autonomously reviewed the literature based on the specified criteria for inclusion and exclusion and completed the process of data extraction, data verification, and quality evaluation. Meta-analysis was performed using RevMan 5.4 and Stata MP 17, while the assessment of risk of bias was carried out utilizing the Risk of Bias version 2 tool (RoB2).

Results

The meta-analysis involved 47 RCTs, encompassing 2,190 patients overall. The indexes indicated that rTMS has the potential to decrease the severity of non-fluent aphasia in stroke patients, including improvement of the capability of repetition, naming, and spontaneous language. The determination of BDNF in the serum of patients was also increased. In addition, rTMS reduced the likelihood of depression in stroke patients.

Conclusion

To summarize the relevant studies, rTMS has significant effects on improving the language abilities of stroke patients suffering from non-fluent aphasia, including the abilities of repetition, naming, and spontaneous language.

A Review of Poststroke Aphasia Recovery and Treatment Options

Poststroke aphasia, which impacts expressive and receptive communication, can have detrimental effects on the psychosocial well-being and the quality of life of those affected. Aphasia recovery is multidimensional and can be influenced by several baseline, stroke-related, and treatment-related factors, including preexisting cerebrovascular conditions, stroke size and location, and amount of therapy received. Importantly, aphasia recovery can continue for many years after aphasia onset. Behavioral speech and language therapy with a speech-language pathologist is the most common form of aphasia therapy. In this review, the authors also discuss augmentative treatment methodologies, collaborative goal setting frameworks, and recommendations for future research.

Neuromodulation for Post-Stroke Motor Recovery: a Narrative Review of Invasive and Non‑Invasive Tools

PURPOSE OF REVIEW

Stroke remains a leading disabling condition, and many survivors have permanent disability despite acute stroke treatment and subsequent standard-of-care rehabilitation therapies. Adjunctive neuromodulation is an emerging frontier in the field of stroke recovery. In this narrative review, we aim to highlight and summarize various neuromodulation techniques currently being investigated to enhance recovery and reduce impairment in patients with stroke.

RECENT FINDINGS

For motor recovery, repetitive transcranial magnetic simulation (rTMS) and direct current stimulation (tDCS) have shown promising results in many smaller-scale trials. Still, their efficacy has yet to be proven in large-scale pivotal trials. A promising large-scale study investigating higher dose tDCS combined with constraint movement therapy to enhance motor recovery is currently underway. MRI-guided tDCS studies in subacute and chronic post-stroke aphasia showed promising benefits for picture-naming recovery. rTMS, particularly inhibitory stimulation over the contralesional homolog, could represent a pathway forward in post-stroke motor recovery in the setting of a well-designed and adequately powered clinical trial. Recently evidenced-based guideline actually supported Level A (definite efficacy) for the use of low-frequency rTMS of the primary motor cortex for hand motor recovery in the post-acute stage of stroke based on the meta-analysis result. Adjunctive vagal nerve stimulation has recently received FDA approval to enhance upper limb motor recovery in chronic ischemic stroke with moderate impairment, and progress has been made to implement it in real-world practice. Despite a few small and large-scale studies in epidural stimulation (EDS), further research on the utilization of EDS in post-stroke recovery is needed. Deep brain stimulation or stent-based neuromodulation has yet to be further tested regarding safety and efficacy. Adjunctive neuromodulation to rehabilitation therapy is a promising avenue for promoting post-stroke recovery and decreasing the overall burden of disability. The pipeline for neuromodulation technology remains strong as they span from the preclinical stage to the post-market stage. We are optimistic to see that more neuromodulation tools will be available to stroke survivors in the not-to-distant future.

Past, present, and future of deep transcranial magnetic stimulation: A review in psychiatric and neurological disorders

Deep transcranial magnetic stimulation (DTMS) is a new non-invasive neuromodulation technique based on repetitive transcranial magnetic stimulation tech-nology. The new H-coil has significant advantages in the treatment and mechanism research of psychiatric and neurological disorders. This is due to its deep stimulation site and wide range of action. This paper reviews the clinical progress of DTMS in psychiatric and neurological disorders such as Parkinson's disease, Alzheimer's disease, post-stroke motor dysfunction, aphasia, and other neurological disorders, as well as anxiety, depression, and schizophrenia.

Current evidence, clinical applications, and future directions of transcranial magnetic stimulation as a treatment for ischemic stroke

Transcranial magnetic stimulation (TMS) is a non-invasive brain neurostimulation technique that can be used as one of the adjunctive treatment techniques for neurological recovery after stroke. Animal studies have shown that TMS treatment of rats with middle cerebral artery occlusion (MCAO) model reduced cerebral infarct volume and improved neurological dysfunction in model rats. In addition, clinical case reports have also shown that TMS treatment has positive neuroprotective effects in stroke patients, improving a variety of post-stroke neurological deficits such as motor function, swallowing, cognitive function, speech function, central post-stroke pain, spasticity, and other post-stroke sequelae. However, even though numerous studies have shown a neuroprotective effect of TMS in stroke patients, its possible neuroprotective mechanism is not clear. Therefore, in this review, we describe the potential mechanisms of TMS to improve neurological function in terms of neurogenesis, angiogenesis, anti-inflammation, antioxidant, and anti-apoptosis, and provide insight into the current clinical application of TMS in multiple neurological dysfunctions in stroke. Finally, some of the current challenges faced by TMS are summarized and some suggestions for its future research directions are made.

Continuous theta burst stimulation-induced suppression of the right fronto-thalamic-cerebellar circuit accompanies improvement in language performance in poststroke aphasia: A resting-state fMRI study

Background

Continuous theta burst stimulation (cTBS) is a specific paradigm of repetitive transcranial magnetic stimulation (rTMS) with an inhibitory effect on cortical excitability for up to 60 min after less than 1 min of stimulation. The right posterior superior temporal gyrus (pSTG), homotopic to Wernicke's area in the left hemisphere, may be a potential stimulation target based on its critical role in semantic processing. The objective of this study was to explore whether cTBS over the right pSTG can promote language improvements in aphasic patients and the underlying mechanism.

Methods

A total of 34 subjects with aphasia were randomly assigned to undergo 15 sessions of either 40-s inhibitory cTBS over the right pSTG (the cTBS group) or sham stimulation (the sham group), followed by 30 min of speech and language therapy. Subjects underwent resting-state functional magnetic resonance imaging (rs-fMRI), and the aphasia quotient (AQ) of the Chinese version of the Western Aphasia Battery (WAB) was calculated before and after the intervention. This randomized controlled trial was registered in the Chinese Clinical Trial Registry (No. ChiCTR210052962).

Results

After treatment, the language performance of the cTBS group was higher than that of the sham group in terms of the WAB-AQ score (p = 0.010) and the WAB scores for auditory comprehension (p = 0.022) and repetition (p = 0.035). The fractional amplitude of low-frequency fluctuations (fALFF) was significantly decreased in the pars triangularis of the inferior frontal gyrus (IFG), right middle frontal gyrus, right thalamus, and left cerebellar crus I. Clusters in the left orbitofrontal cortex exhibited increased fALFF. The change in WAB comprehension scores were significantly correlated with the change in the fALFF of the right IFG pars triangularis in both groups. Greatly increased functional connectivity was observed between the right pars triangularis and left paracingulate gyrus and between the right pSTG and right angular gyrus and the posterior cingulate gyrus with pre-and post-treatment between the two groups.

Conclusion

Our findings indicate that cTBS of the right pSTG may improve language production by suppressing intrinsic activity of the right fronto-thalamic-cerebellar circuit and enhancing the involvement of the right temporoparietal region.

Targeted neurorehabilitation strategies in post-stroke aphasia

BACKGROUND

Aphasia is a debilitating language impairment, affecting millions of people worldwide. About 40% of stroke survivors develop chronic aphasia, resulting in life-long disability.

OBJECTIVE

This review examines extrinsic and intrinsic neuromodulation techniques, aimed at enhancing the effects of speech and language therapies in stroke survivors with aphasia.

METHODS

We discuss the available evidence supporting the use of transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation, and functional MRI (fMRI) real-time neurofeedback in aphasia rehabilitation.

RESULTS

This review systematically evaluates studies focusing on efficacy and implementation of specialized methods for post-treatment outcome optimization and transfer to functional skills. It considers stimulation target determination and various targeting approaches. The translation of neuromodulation interventions to clinical practice is explored, emphasizing generalization and functional communication. The review also covers real-time fMRI neurofeedback, discussing current evidence for efficacy and essential implementation parameters. Finally, we address future directions for neuromodulation research in aphasia.

CONCLUSIONS

This comprehensive review aims to serve as a resource for a broad audience of researchers and clinicians interested in incorporating neuromodulation for advancing aphasia care.