Exploring symptomatology and innovative treatment modalities for prefrontal cortex lesions: a systematic review

BACKGROUND

Pre-frontal cortex operates a combination of emotional, cognitive and behavioural functions. Understanding the symptoms of pre-frontal cortex lesions serves as paramount for accurate diagnosis and management.

AIMS

This review aims to determine an association between the causes of prefrontal cortex lesions and the resulting symptoms, as well as the ideal form of treatment.

STUDY DESIGN

A systematic review through utilisation of 3 databases was done using the keywords "Prefrontal cortex lesions," "dysfunction," "symptoms," &" treatment".

METHODOLOGY

RCTs, observational studies, and systematic reviews were searched using Cochrane/EMBASE, PubMed/Medline, and Pedro between 1948 and2024. Studies published in English only were included, and two reviewers were involved in the data extraction process.

RESULTS

Results showed a notable correlation between right-handed individuals and prefrontal cortex lesions with cognition impairment, particularly executive dysfunction, being the most prevalent symptom. Emotional instability followed as the second most common issue, while aphasia remained the primary language deficit. Noninvasive brain stimulation emerged as an effective treatment option for various prefrontal cortex-related disorders.

CONCLUSION

Further investigation is needed to understand the mechanism linking handedness to lesion occurrence. Noninvasive brain stimulation should be prioritised for treating prefrontal injuries.

Effects of different modalities of transcranial magnetic stimulation on post-stroke cognitive impairment: a network meta-analysis

OBJECTIVE

The study aimed to evaluate, using a network meta-analysis, the effects of different transcranial magnetic stimulation (TMS) modalities on improving cognitive function after stroke.

METHODS

Computer searches of the Cochrane Library, PubMed, Web of Science, Embass, Google Scholar, CNKI, and Wanfang databases were conducted to collect randomized controlled clinical studies on the use of TMS to improve cognitive function in stroke patients, published from the time of database construction to November 2023.

RESULTS

A total of 29 studies and 2123 patients were included, comprising five interventions: high-frequency rTMS (HF-rTMS), low-frequency rTMS (LF-rTMS), intermittent theta rhythm stimulation (iTBS), sham stimulation (SS), and conventional rehabilitation therapy (CRT). A reticulated meta-analysis showed that the rankings of different TMS intervention modalities in terms of the Montreal Cognitive Assessment (MoCA) scores, Mini-Mental State Examination scores (MMSE), and Modified Barthel Index (MBI) scores were: HF-rTMS > LF-rTMS > iTBS > SS > CRT; the rankings of different TMS intervention modalities in terms of the event-related potential P300. amplitude scores were HF-rTMS > LF-rTMS > iTBS > CRT > SS; the rankings of different TMS intervention modalities in terms of the P300 latency scores were: iTBS > HF-rTMS > LF-rTMS > SS > CRT. Subgroup analyses of secondary outcome indicators showed that HF-rTMS significantly improved Rivermead Behavior Memory Test scores and Functional Independence Measurement-Cognitive scores.

CONCLUSIONS

High-frequency TMS stimulation has a better overall effect on improving cognitive functions and activities of daily living, such as attention and memory in stroke patients.

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.

Efficacy of different rehabilitation therapies on post-stroke aphasia patients: A network meta-analysis

BACKGROUND

Although several rehabilitation interventions are effective in post-stroke aphasia (PSA), the efficacy of different rehabilitation interventions compared to each other remains controversial. Here, we aimed to compare the effectiveness of varying rehabilitation interventions in PSA.

METHODS

Randomized controlled trials on 8 kinds of rehabilitation interventions to improve speech function in patients with PSA were searched by computer from 10 databases, including PubMed, Web of Science, Cochrane, OVID, CINAHL, Embase, CNKI, WanFang, CBM, and VIP. The search scope was from the establishment of the database to August 2023. The literature screening, extraction of basic information, and quality assessment of the literature were conducted independently by 2 researchers. Network meta-analysis (NMA) was performed using Stata 17.0 software.

RESULTS

Fifty-four studies involving 2688 patients with PSA were included. The results of NMA showed that: ① in terms of improving the severity of aphasia, the therapeutic effects of repetitive transcranial magnetic stimulation were the most significant; ② motor imagery therapy was the most effective in improving spontaneous speech, repetition, and naming ability; ③ in terms of improving listening comprehension ability, the therapeutic effects of mirror neuron therapy was the most significant.

CONCLUSION

The 8 rehabilitation interventions have different focuses in improving the speech function of PSA patients, and the clinical therapists can select the optimal rehabilitation interventions in a targeted manner according to the results of this NMA and the patients' conditions and other relevant factors.

Efficacy of repetitive transcranial magnetic stimulation with different application parameters for post-stroke cognitive impairment: a systematic review

Background

Cognitive impairment is a prevalent consequence of stroke, seriously affecting recovery and quality of life while imposing substantial burdens on both patients' families and society. Repetitive transcranial magnetic stimulation (rTMS) has emerged as an effective intervention for post-stroke cognitive impairment (PSCI). However, the a lack of standardized and explicit guidelines regarding rTMS application parameters. Therefore, this study systematically evaluated the efficacy of various parameters of rTMS in treating PSCI and explored its potential mechanism.

Methods

We conducted a comprehensive search across seven scientific databases, namely China National Knowledge Infrastructure (CNKI), Wanfang Data Knowledge Service Platform (Wanfang), China Science and Technology Journal Database (VIP), Web of Science, PubMed, Embase, and Cochrane Library, to identify randomized controlled trials (RCTs) investigating the efficacy of rTMS for PSCI. The search encompassed the period from database creation until July 28, 2023. To evaluate the risk of bias in included studies, we employed the Cochrane recommended risk of bias assessment tool. Furthermore, we extracted relevant clinical application parameters associated with rTMS and performed comparative analyses to assess their therapeutic effects under different parameter settings.

Results

The present study included 45 RCTs involving a total of 3,066 patients with PSCI. Both high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) and low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) demonstrated safety and efficacy, yet failed to exhibit significant differentiation in terms of cognitive improvement. Furthermore, intermittent theta burst stimulation (iTBS), although yielding positive results, did not surpass traditional rTMS in effectiveness. Combining HF-rTMS with LF-rTMS resulted in superior efficacy compared to single rTMS intervention. Moreover, the combination of rTMS with other cognitive therapies exhibited potential for enhanced benefits among patients.

Conclusion

rTMS can effectively and safely enhance cognitive function, improve quality of life, and enhance activities of daily living in patients with PSCI. Furthermore, the combination of rTMS with other conventional rehabilitation methods can yield additional positive effects. However, due to insufficient evidence, an optimal parameter protocol for rTMS can not be currently recommended. Future research should prioritize orthogonal experimental design methods that incorporate multiple parameters and levels to determine the optimal parameter protocol for rTMS in PSCI.

A literature review and meta-analysis of the optimal factors study of repetitive transcranial magnetic stimulation in post-infarction aphasia

BACKGROUND

The existing literature indicates that repetitive transcranial magnetic stimulation (rTMS) can potentially enhance the prognosis of poststroke aphasia (PSA). Nevertheless, these investigations did not identify the most effective parameters or settings for achieving optimal treatment outcomes. This study involved a meta-analysis aimed to identify the optimal variables for rTMS in treating post-infarction aphasia to guide the use of rTMS in rehabilitating PSA.

METHODS

PubMed, Embase, and Cochrane Library databases were searched from inception to May 2023, and articles were reviewed manually using subject words and free words and supplemented with references from the included literature to obtain additional relevant literature. The search terms included "poststroke aphasia" and "repetitive transcranial magnetic stimulation (rTMS)" repetitive transcranial magnetic stimulation. Additionally, a review of the reference lists of previously published systematic reviews identified through the Cochrane Database of Systematic Reviews (search terms: poststroke aphasia, rTMS; restrictions: none) and PubMed (search terms: poststroke aphasia, rTMSs; restrictions: systematic review or meta-analysis) was performed. Information from studies involving different doses of rTMS in PSA was independently screened and extracted by 2 researchers.

RESULTS

This meta-analysis included 387 participants with PSA across 18 randomized controlled trials. The results showed that the total pulse had a trend toward a significant correlation with the treatment effect (P = 0.088), while all other variables did not correlate significantly. When rTMS was not grouped by stimulus parameter and location, our nonlinear results showed that when the total pulses were 40,000 (standardized mean difference (SMD):1.86, 95% credible interval (CrI) 0.50 to 3.33), the pulse/session was 1000 (SMD:1.05, 95% CrI 0.55-1.57), and an RMT of 80% (SMD:1.08, 95% CrI 0.60-1.57) had the best treatment effect. When rTMS was grouped by stimulus parameters and location, our nonlinear results showed that when the total low-frequency (LF)-rTMS-right inferior frontal gyrus (RIFG) pulse was 40,000 (SMD:1.76, 95% CrI:0.36-3.29), the pulse/session was 1000 (SMD:1.06, 95% CrI:0.54-1.59). Optimal results were obtained with an RMT of 80% (SMD:1.14, 95% CrI 0.54 - 1.76).

CONCLUSIONS

The optimal treatment effects of rTMS for PSA may be obtained with a total pulse of 40,000, a pulse/session of 1000, and an RMT of 80%. Further rigorous randomized controlled studies are required to substantiate the validity of these results.

Does SLT combined with NIBS enhance naming recovery in post-stroke aphasia? A meta-analysis and systematic review

BACKGROUND

Non-invasive brain stimulation has been widely used as an adjunctive treatment for aphasia following stroke.

OBJECTIVE

The aim of this study was to investigate the effect of non-invasive brain stimulation as an adjunctive treatment on naming function in aphasia following stroke.

METHODS

This review included randomized controlled trials (RCTs) involving 5 databases (Web of Science, Embase, Cochrane Library, OVID and PubMed) that investigated the effects of electrical stimulation on stroke patients. The search included literature published up to November 2023.

RESULTS

We identified 18 studies, and the standardized mean differences (SMDs) showed that the effect sizes of TMS and tDCS were small to medium. Moreover, the treatment effects persisted over time, indicating long-term efficacy.

CONCLUSION

This study suggested that NIBS combined with speech and language therapy can effectively promote the recovery of naming function in patients with post-stroke aphasia (PSA) and that the effects are long lasting.

Evidence of rTMS for Motor or Cognitive Stroke Recovery: Hype or Hope?

BACKGROUND

Evidence of efficacy of repetitive transcranial magnetic stimulation (rTMS) for stroke recovery is hampered by an unexplained variability of reported effect sizes and an insufficient understanding of mechanisms of action. We aimed to (1) briefly summarize evidence of efficacy, (2) identify critical factors to explain the reported variation in effects, and (3) provide mechanism-based recommendations for future trials.

METHODS

We performed a systematic review of the literature according to Cochrane and PRISMA Protocols. We included trials with ≥10 patients per treatment group. We classified outcome measures according to the International Classification of Functioning, Disability, and Health. Meta-analysis was done when at least 3 trials were reported on the same construct. In case of significant summary effect sizes with significant heterogeneity, we used sensitivity analyses to test for correlations and differences between found individual effect sizes and possible effect modifiers such as patient-, repetitive transcranial magnetic stimulation-, and trial characteristics.

RESULTS

We included 57 articles (N=2595). Funnel plots showed no publication bias. We found significant effect sizes at the level of body function (upper limb synergies, muscle strength, language functioning, global cognitive functioning, visual/spatial inattention) with repetitive transcranial magnetic stimulation within or beyond 3 months after stroke. We also found significant effect sizes at the level of activities. We found no subgroup differences or significant correlations between individual summary effect sizes and any tested possible effect modifier.

CONCLUSIONS

Repetitive transcranial magnetic stimulation holds the potential to benefit a range of motor and cognitive outcomes after stroke, but the evidence of efficacy is challenged by unexplained heterogeneity across many small sampled trials. We propose large trials with the collection of individual patient data on baseline severity and brain network integrity with sufficiently powered subgroup analyses, as well as protocolized time-locked training of the target behavior. Additional neurophysiological and biomechanical data may help in understanding mechanisms and identifying biomarkers of treatment efficacy.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: CRD42022300330.

Therapies and Challenges in the Post-Stroke Aphasia Rehabilitation Arena: Current and Future Prospects

Aphasia is a serious consequence of stroke that results in a breakdown in communication. The course of aphasia recovery differs between afflicted individuals, and responsiveness to treatment cannot be predicted. Aphasiologists continue to investigate numerous behavioral treatment protocols that have shifted their focus to complimentary rehabilitation strategies. The aim of this study is threefold. First, to summarize the different categories of aphasia interventions post-stroke, considering their respective protocols, and present available evidence on the effectiveness of those protocols. Second, to document the challenges regarding the prediction of aphasia treatment response post-stroke in individual patients. Third, to report the challenges faced by researchers in recruiting people with aphasia (PWA) for treatment studies, and provide recommendations on how to increase participant recruitment and retention. This study provides up-to-date information on (i) effective therapies and aphasia recovery processes, and (ii) research recruitment hurdles together with potential strategies for overcoming them.

Comparing the efficiency of speech and language therapy and transcranial magnetic stimulation for treating Broca's aphasia

OBJECTIVES

Aphasia is an acquired language-cognitive disorder that highly affects an individual's speech, language, and communication skills. Recovery from aphasia requires attentive treatment since it is a long and dynamic process. This study aimed to show interactive benefits of combining classical intervention strategies with new technological approaches and demonstrating their effectiveness.

MATERIALS AND METHODS

A total of 40 individuals with Broca's aphasia were included in the study. The participants were divided into Application-1 Speech and Language Therapy, Application-2 Transcranial Magnetic Stimulation, Application-3 (consecutive Transcranial Magnetic Stimulation and Speech and Language Therapy), and Application-4 (Control Group) experimental groups, with 10 participants in each group.

RESULTS

Analysis indicated that individuals in the group in which Transcranial Magnetic Stimulation and Speech and Language Therapy were applied consecutively had further increases in speech fluency, repetition, and naming scores from pre-test to post-test (p<0.01). Picture naming and quality-of-life communication scores of individuals in the group in which Speech and Language Therapy was performed increased further from pre-test to post-test (p<0.01).

CONCLUSIONS

The results of the study showed a positive effect on language skills, naming scores, and participation in social life of Turkish-speaking aphasic individuals with the Speech and Language Therapy and Transcranial Magnetic Stimulation methods. The use of Transcranial Magnetic Stimulation alone is insufficient in this context. Although Speech and Language Therapy alone is effective in naming ability, Transcranial Magnetic Stimulation in addition to Speech and Language Therapy significantly increases the gain obtained with therapies.

Repetitive transcranial magnetic stimulation for hypokinetic dysarthria in Parkinson's disease enhances white matter integrity of the auditory-motor loop

BACKGROUND AND PURPOSE

In our previous study, repeated sessions of repetitive transcranial magnetic stimulation (rTMS) over the auditory feedback area were shown to improve hypokinetic dysarthria (HD) in Parkinson's disease (PD) and led to changes in functional connectivity within the left-sided articulatory networks. We analyzed data from this previous study and assessed the effects of rTMS for HD in PD on the diffusion parameters of the left anterior arcuate fasciculus (AAF), which connects the auditory feedback area with motor regions involved in articulation.

METHODS

Patients were assigned to 10 sessions of real or sham 1-Hz stimulation over the right posterior superior temporal gyrus. Stimulation effects were evaluated using magnetic resonance diffusion tensor imaging and by a speech therapist using a validated tool (Phonetics score of the Dysarthric Profile) at baseline, immediately after 2 weeks of stimulation, and at follow-up visits at Weeks 6 and 10 after the baseline.

RESULTS

Altogether, data from 33 patients were analyzed. A linear mixed model revealed significant time-by-group interaction (p = 0.006) for the relative changes of fractional anisotropy of the AAF; the value increases were associated with the temporal evolution of the Phonetics score (R = 0.367, p = 0.028) in the real stimulation group.

CONCLUSIONS

Real rTMS treatment for HD in PD as compared to sham stimulation led to increases of white matter integrity of the auditory-motor loop during the 2-month follow-up period. The changes were related to motor speech improvements.

Speech assessment tool methods for speech impaired children: a systematic literature review on the state-of-the-art in Speech impairment analysis

Speech is a powerful, natural mode of communication that facilitates effective interactions in human societies. However, when fluency or flow of speech is affected or interrupted, it leads to speech impairment. There are several types of speech impairment depending on the speech pattern and range from mild to severe. Childhood apraxia of speech (CAS) is the most common speech disorder in children, with 1 out of 12 children diagnosed globally. Significant advancements in speech assessment tools have been reported to assist speech-language pathologists diagnosis speech impairment. In recent years, speech assessment tools have also gained popularity among pediatricians and teachers who work with preschoolers. Automatic speech tools can be more accurate for detecting speech sound disorders (SSD) than human-based speech assessment methods. This systematic literature review covers 88 studies, including more than 500 children, infants, toddlers, and a few adolescents, (both male and female) (age = 0-17) representing speech impairment from more than 10 countries. It discusses the state-of-the-art speech assessment methods, including tools, techniques, and protocols for speech-impaired children. Additionally, this review summarizes notable outcomes in detecting speech impairments using said assessment methods and discusses various limitations such as universality, reliability, and validity. Finally, we consider the challenges and future directions for speech impairment assessment tool research.

Repetitive Transcranial Magnetic Stimulation in Post-stroke Aphasia: Comparative Evaluation of Inhibitory and Excitatory Therapeutic Protocols: Narrative Review

OBJECTIVE

Aphasia is a serious consequence of stroke resulting in difficulties in using language for communication with negative effects on patients' quality of life. The use of non-invasive repetitive transcranial magnetic stimulation (rTMS) is a novel approach in aphasia therapy, based on the knowledge gained by functional imaging technics of the brain.

AIM

This review evaluates the effectiveness of rTMS on aphasia therapy according to the results of English language studies that have been published in the databases PubMed/Medline, Scopus, and Web of Science from 2011 to 2021.

RESULTS

Twenty-seven studies were included in the review with 672 participants. The studies mainly concern the application of inhibitory rTMS on the right inferior frontal gyrus (rIFG) in the subacute and chronic phase, as well as excitatory rTMS of the unaffected language areas of the left cerebral hemisphere in the chronic phase after stroke. Most of the studies concluded that there was statistically significant improvement in various parameters of language including confrontation naming, repetition, and aphasia quotient. Three studies published results that doubt the effectiveness of rTMS.

CONCLUSION

rTMS is a safe therapeutic method for aphasia treatment in the subacute and chronic phases after stroke. Its effectiveness is immediate as well as distant with a gradually decreasing therapeutic effect. Moreover, rTMS may supplement speech and language therapy as a priming factor. The most recognized method at this point in time is the application of suppressive rTMS on the right inferior frontal gyrus in combination with speech and language therapy.

Management of communication disability in the first 90 days after stroke: a scoping review

INTRODUCTION

People with communication disability after stroke need interventions to optimise healthcare communication and rehabilitation outcomes. Current evidence syntheses do not adequately inform the management of communication disability during the first 90 days post-stroke.

PURPOSE

To explore the scope of literature for the management of communication disability in the first 90 days after stroke.

MATERIALS AND METHODS

A scoping review was conducted using a systematic keyword search of six databases. A descriptive synthesis was generated using communication-related domains related to the biopsychosocial framework of the International Classification of Functioning, Disability, and Health (ICF).

RESULTS

A total of 129 studies met eligibility criteria. Aphasia was the most frequently addressed communication disability after stroke (76/129 studies) with a paucity of evidence investigating other acquired neurogenic communication impairments. Management predominantly focused on communication-related: body functions and structures (62 studies) (e.g., linguistic-behavioural therapies), followed by environmental factors (39 studies) (e.g., communication partner training/support); activities and participation (15 studies) (e.g., augmentative and alternative communication); and personal factors (13 studies) (e.g., assessment of depression after aphasia).

CONCLUSION

A coordinated, integrated approach to developing and testing acute and subacute interventions for all communication disabilities across all communication-related domains is required.IMPLICATIONS FOR REHABILITATIONInterdisciplinary stroke clinicians need to manage communication disabilities in the first 90 days after stroke to optimise healthcare communication and rehabilitation outcomes.There is some evidence to guide clinicians in aphasia management but less in other disabilities of speech and cognitive functioning.Most interventions to inform clinical practice address communication-related body functions and structures (e.g., linguistic and speech therapies). Clinicians need to address all domains and more evidence is needed to address environmental factors (e.g., communication support); activities and participation (e.g., person-centred goal setting); and personal factors (e.g., psychological care).

Effects of simultaneous use of m-NMES and language training on brain functional connectivity in stroke patients with aphasia: A randomized controlled clinical trial

Introduction

The m-NMES had been demonstrated to redistribute brain resources and induce plastic changes in the stroke patients. However, the physiological mechanism and clinical efficacy of m-NMES combination with existing clinical rehabilitation programs remains unclear in patients with aphasia after stroke. This study aimed to investigate the effects of simultaneous use of m-NMES and language training (m-NMES-LT) with on cerebral oscillations and brain connection, as well as the effect on clinical efficacy.

Materials and methods

Total 21 right–handed adult patients with aphasia were randomly assigned to language training (LT) group and m-NMES-LT group, and tissue concentration of oxyhemoglobin and deoxyhemoglobin oscillations were measured by functional near-infrared spectroscopy in resting and treatment state during three consecutive weeks. Five characteristic frequency signals (I, 0.6–2 Hz; II, 0.145–0.6 Hz; III, 0.052–0.145 Hz; IV, 0.021–0.052 Hz; and V, 0.0095–0.021 Hz) were identified using the wavelet method. The wavelet amplitude (WA) and wavelet phase coherence (WPCO) were calculated to describe the frequency-specific cortical activities.

Results

The m-NMES-LT induced significantly higher WA values in contralesional PFC in intervals I, II, and V, and ipsilesional MC in intervals I-V than the resting state. The WPCO values between ipsilesional PFC-MC in interval III-IV, and between bilateral MC in interval III-IV were significantly higher than resting state. In addition, there was a significant positive correlation between WPCO and Western Aphasia Battery in m-NMES-LT group.

Conclusion

The language training combined with neuromuscular electrical stimulation on median nerve could improve and achieve higher clinical efficacy for aphasia. This is attributed to the m-NMES-LT could enhance cortical activation and brain functional connectivity in patients with aphasia, which was derived from myogenic, neurogenic, and endothelial cell metabolic activities.

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

PURPOSE

Aphasia-acquired loss of the ability to understand or express language-is a common and debilitating neurological consequence of stroke. Evidence suggests that transcranial magnetic stimulation (TMS) can significantly improve language outcomes in patients with aphasia. Repetitive transcranial magnetic stimulation (rTMS) has been reported to improve naming in chronic stroke patients with nonfluent aphasia since 2005.

METHODS

We conducted a systematic review and meta-analyses of TMS treatment studies in patients with aphasia. Eight electronic databases (PubMed, Medline, Embase, Scopus, ScienceDirect, Cochrane Central Register of Controlled Trials, Journals@Ovid, and clinicaltrials.gov) were searched for articles. Relevant studies were further evaluated, and studies that met inclusion criteria were reviewed. The searches were limited to human studies written in English and published between January 1960 and January 2020. In keeping with the main objective of this review, we included all studies that carried out treatment using rTMS in stroke patients with aphasia, regardless of the trial (or experimental) design of the study. Studies that implemented between-subject or randomized controlled (RCT) design, cross-over trials, and within-subject or pre-post trials were all included. Standard mean difference (SMD) for changes in picture naming accuracy was estimated.

RESULTS

The literature search yielded 423 studies. Fifty articles were further evaluated to be included. Eleven met all inclusion criteria and were chosen for review. Eleven eligible studies involving 242 stroke patients were identified in this meta-analysis. Further analyses demonstrated prominent effects for the naming subtest (SMD = 1.26, 95% CI = 0.80 to 1.71, p = 0.01), with heterogeneity (I² = 69.101%). The meta-analysis continued to show that there was a statistically significant effect of rTMS compared with sham rTMS on the severity of aphasia. None of the patients from the 11 included articles reported adverse effects from rTMS.

CONCLUSIONS

There are some strong studies evaluating the efficacy of rTMS in stroke patients but further research is required to fully establish the usefulness of this treatment. This meta-analysis indicates a clinically positive effect of rTMS with or without speech and language therapy (SLT) for patients with aphasia following stroke in overall language function and expressive language, including naming, repetition, writing, and comprehension. Low-frequency (1 Hz) rTMS over the unaffected hemisphere is effective and compatible with the concept of interhemispheric inhibition. Moreover, the treatment of 1 Hz rTMS for patients with aphasia after stroke was safe.

The multidimensional nature of aphasia recovery post-stroke

Language is not a single function, but instead results from interactions between neural representations and computations that can be damaged independently of each other. Although there is now clear evidence that the language profile in post-stroke aphasia reflects graded variations along multiple underlying dimensions ('components'), it is still entirely unknown if these distinct language components have different recovery trajectories and rely on the same, or different, neural regions during aphasia recovery. Accordingly, this study examined whether language components in the subacute stage: (i) mirror those observed in the chronic stage; (ii) recover together in a homogeneous manner; and (iii) have recovery trajectories that relate to changing activation in distinct or overlapping underlying brain regions. We analysed longitudinal data from 26 individuals with mild-moderate aphasia following left hemispheric infarct who underwent functional MRI and behavioural testing at ∼2 weeks and ∼4 months post-stroke. The language profiles in early post-stroke aphasia reflected three orthogonal principal components consisting of fluency, semantic/executive function and phonology. These components did not recover in a singular, homogeneous manner; rather, their longitudinal trajectories were uncorrelated, suggesting that aphasia recovery is heterogeneous and multidimensional. Mean regional brain activation during overt speech production in unlesioned areas was compared with patient scores on the three principal components of language at both the early and late time points. In addition, the change in brain activation over time was compared with the change on each of the principal component scores, both before and after controlling for baseline scores. We found that different language components were associated with changing activation in multiple, non-overlapping bilateral brain regions during aphasia recovery. Specifically, fluency recovery was associated with increasing activation in bilateral middle frontal gyri and right temporo-occipital middle temporal gyrus; semantic/executive recovery was associated with reducing activation in bilateral anterior temporal lobes; while phonology recovery was associated with reducing activation in bilateral precentral gyri, dorso-medial frontal poles and the precuneus. Overlapping clusters in the ventromedial prefrontal cortex were positively associated with fluency recovery but negatively associated with semantic/executive and phonology recovery. This combination of detailed behavioural and functional MRI data provides novel insights into the neural basis of aphasia recovery. Because different aspects of language seem to rely on different neural regions for recovery, treatment strategies that target the same neural region in all stroke survivors with aphasia might be entirely ineffective or even impair recovery, depending on the specific language profile of each individual patient.

Functional Network Changes After High-Frequency rTMS Over the Most Activated Speech-Related Area Combined With Speech Therapy in Chronic Stroke With Non-fluent Aphasia

OBJECTIVE

High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) to the lesional hemisphere requires prudence in selecting the appropriate stimulation spot. Functional near-IR spectroscopy (fNIRS) can be used in both selecting the stimulation spot and assessing the changes of the brain network. This study aimed to evaluate the effect of HF-rTMS on the most activated spot identified with fNIRS and assess the changes of brain functional network in the patients with poststroke aphasia.

METHODS

A total of five patients received HF-rTMS to the most activated area on the lesional hemisphere, followed by 30 min of speech therapy for 10 days. The Korean version of the Western aphasia battery (K-WAB) and fNIRS evaluation were done 1 day before the treatment, 1 day and 1 month after the last treatment session. Changes of K-WAB and paired cortical interaction and brain network analysis using graph theory were assessed.

RESULTS

Aphasia quotient in K-WAB significantly increased after the treatment (P = 0.043). The correlation analysis of cortical interactions showed increased connectivity between language production and processing areas. Clustering coefficients of the left hemisphere were increased over a sparsity range between 0.45 and 0.58 (0.015 < p < 0.031), whereas the clustering coefficients of the right hemisphere, decreased over a sparsity range 0.15-0.87 (0.063 < p < 0.095). The global efficiency became lower over a network sparsity range between 0.47 and 0.75 (0.015 < p < 0.063).

CONCLUSION

Improvement of language function and changes of corticocortical interaction between language-related cortical areas were observed after HF-rTMS on the most activated area identified by fNIRS with combined speech therapy in the patients with poststroke aphasia.

The Effectiveness of Transcranial Magnetic Stimulation (TMS) Paradigms as Treatment Options for Recovery of Language Deficits in Chronic Poststroke Aphasia

Background

In an effort to boost aphasia recovery, modern rehabilitation, in addition to speech and language therapy (SALT), is increasingly incorporating noninvasive methods of brain stimulation. The present study is aimed at investigating the effectiveness of two paradigms of neuronavigated repetitive transcranial magnetic stimulation (rTMS): (i) 1 Hz rTMS and (ii) continuous theta burst stimulation (cTBS) each as a standalone treatment for chronic aphasia poststroke.

Methods

A single subject experimental design (SSED) trial was carried out in which six people with aphasia (PWA) were recruited, following a single left hemispheric stroke more than six months prior to the study. Three individuals were treated with 1 Hz rTMS, and the remaining three were treated with cTBS. In all cases, TMS was applied over the right pars triangularis (pTr). Language assessment, with standardized and functional measures, and cognitive evaluations were carried out at four time points: twice prior to treatment (baseline), one day immediately posttreatment, and at follow-up two months after treatment was terminated. Quality of life (QoL) was also assessed at baseline and two months posttreatment. In addition, one of the participants with severe global aphasia was followed up again one and two years posttherapy.

Results

For all participants, both rTMS paradigms (1 Hz rTMS and cTBS) generated trends towards improvement in several language skills (i.e., verbal receptive language, expressive language, and naming and reading) one day after treatment and/or two months after therapy. Rated QoL remained stable in three individuals, but for the other three, the communication scores of the QoL were reduced, while two of them also showed a decline in the psychological scores. The participant that was treated with cTBS and followed for up to two years showed that the significant improvement she had initially exhibited in comprehension and reading skills two months after TMS (1^st follow-up) was sustained for at least up to two years.

Conclusion

From the current findings, it is suggested that inhibitory TMS over the right pTr has the potential to drive neuroplastic changes as a standalone treatment that facilitates language recovery in poststroke aphasia.

New Treatment Strategy Using Repetitive Transcranial Magnetic Stimulation for Post-Stroke Aphasia

Repetitive transcranial magnetic stimulation (rTMS) for post-stroke aphasia (PSA) has been suggested to promote improvement of language function when used in combination with rehabilitation. However, many challenges remain. In some reports examined by category of language function, only naming has good evidence of improvement, and the improvement effect on other language modalities is low. Therefore, it is necessary to establish methods that contribute to the improvement of language functions other than naming. Therapeutic methods for PSA based on the mechanism of rTMS are mainly inhibitory stimulation methods for language homologous areas. However, the mechanisms of these methods are controversial when inferred from the process of recovery of language function. Low-frequency rTMS applied to the right hemisphere has been shown to be effective in the chronic phase of PSA, but recent studies of the recovery process of language function indicate that this method is unclear. Therefore, it has been suggested that evaluating brain activity using neuroimaging contributes to confirming the effect of rTMS on PSA and the elucidation of the mechanism of functional improvement. In addition, neuroimaging-based stimulation methods (imaging-based rTMS) may lead to further improvements in language function. Few studies have examined neuroimaging and imaging-based rTMS in PSA, and further research is required. In addition, the stimulation site and stimulation parameters of rTMS are likely to depend on the time from onset to intervention. However, there are no reports of studies in patients between 90 and 180 days after onset. Therefore, research during this period is required. New stimulation methods, such as multiple target methods and the latest neuroimaging methods, may contribute to the establishment of new knowledge and new treatment methods in this field.

Effects of Low-Frequency Repetitive Transcranial Magnetic Stimulation on Language Recovery in Poststroke Survivors With Aphasia: An Updated Meta-analysis

The effects of low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) on treating poststroke aphasia (PSA) remain inconclusive. We aimed to evaluate the efficacy and safety of LF-rTMS on language function poststroke and determine potential factors that may affect treatment effects. Electronic databases, including MEDLINE, EMBASE, and Cochrane Library were searched to identify relevant randomized controlled trials (RCTs) concerning the effects of LF-rTMS on language performance poststroke. We adopted fixed- and random-effects models to estimate intervention effects, which were represented by the Hedges' g and 95% CIs. Subgroup analyses regarding several factors potentially influencing the effects of LF-rTMS on language recovery were also conducted. A total of 14 RCTs involving 374 participants were included in the meta-analysis. The pooled analysis showed the positive and significant effects of LF-rTMS on language function, both short-term (Hedges' g = 0.65; P < .05) and long-term (Hedges' g = 0.46; P < .05). Subgroup analyses demonstrated that LF-rTMS for 20 minutes per day over 10 days yielded the largest effect size (Hedges' g = 1.02; P < .05) and that LF-rTMS significantly improved language performance in the chronic stage after stroke (Hedges' g = 0.55; P < .05). Patients with different native languages might have diverse responses to LF-rTMS treatment efficacy. Additionally, there were significant improvements in language subtests, including naming, repetition, comprehension, and writing. Overall, this updated meta-analysis demonstrated that LF-rTMS has significant positive effects on PSA, with moderate treatment effects. It provides additional evidence to support LF-rTMS as a promising complementary therapy to promote language recovery in PSA.

Effect of High Frequency Transcranial Magnetic Stimulation on Recovery of Chronic Post-Stroke Aphasia

BACKGROUND

Both hemispheres have role in post-stroke aphasia recovery but better recovery is expected with the restoration of function by the left hemisphere. Transcranial stimulation has been used to favor recruitment of left-hemispheric language networks and increase activity of the left hemisphere, thus helps aphasia recovery .

OBJECTIVE

The aim of this study is to evaluate the effect of excitatory repetitive transcranial magnetic stimulation (rTMS) on recovery of post stroke aphasic patients .

MATERIALS AND METHODS

Twenty patients with post stroke chronic aphasia were enrolled in the study. Aphasia severity was assessed using Aphasia Severity Rating Scale (ASRS). Linguistic deficits were assessed using Kasr Al-Aini Arabic Aphasia test (KAAT). Real rTMS was applied three for 10 sessions of 10-Hz stimulation, positioned over the left Broca's area of the affected hemisphere. All patients were evaluated before, after the end of treatment sessions and one month later .

RESULTS

There was a significant improvement in the mean total score and mean scores of components of KAAT scale before, immediately after and after one month of rTMS (P< 0.05). Moreover, there was a significant improvement in mean scores of ASRS before, immediately after and after one month of rTMS (P= 0.000). There was a significant difference in mean scores of ASRS and KAAT before, immediately after the last session and after one month between small, medium and large brain infarcts. (P< 0.05).

CONCLUSION

Excitatory rTMS is a beneficial adjuvant therapy that improves language skills in patients with chronic post-stroke non-fluent aphasia in short and long term. The protocol of this observational study was registered in clinical trial registration: www.ClinicalTrials.gov, identifier: NCT04708197.

A systematic review of repetitive transcranial magnetic stimulation in aphasia rehabilitation: Leads for future studies

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive tool that induces neuromodulation in the brain. Several studies have shown that rTMS improves language recovery in patients with post-stroke aphasia.

OBJECTIVE

This systematic review summarizes the role of rTMS in aphasia rehabilitation.

METHODS

We searched MEDLINE via PubMed and Scopus on 30October, 2020, for English articles (1996-2020). Eligible studies involved post-stroke aphasia rehabilitation with rTMS. In some of these studies, rTMS was also combined with speech therapy.

RESULTS

In total, seven meta-analyses and 59studies (23randomized clinical trials) were included in this systematic review. The methods used in these studies were heterogeneous. Only six studies did not find that rTMS had a significant effect on language performance.

CONCLUSIONS

The evidence from the peer-reviewed literature suggests that rTMS is an effective tool in post-stroke aphasia rehabilitation. However, the precise mechanisms that underlie the effects of rTMS and the reorganization of language networks in patients who have had a stroke remain unclear. We discuss these crucial challenges in the context of future studies.

Non-invasive brain stimulation for speech in Parkinson's disease: A randomized controlled trial

BACKGROUND

Hypokinetic dysarthria is a common but difficult-to-treat symptom of Parkinson's disease (PD).

OBJECTIVES

We evaluated the long-term effects of multiple-session repetitive transcranial magnetic stimulation on hypokinetic dysarthria in PD. Neural mechanisms of stimulation were assessed by functional MRI.

METHODS

A randomized parallel-group sham stimulation-controlled design was used. Patients were randomly assigned to ten sessions (2 weeks) of real (1 Hz) or sham stimulation over the right superior temporal gyrus. Stimulation effects were evaluated at weeks 2, 6, and 10 after the baseline assessment. Articulation, prosody, and speech intelligibility were quantified by speech therapist using a validated tool (Phonetics score of the Dysarthric Profile). Activations of the speech network regions and intrinsic connectivity were assessed using 3T MRI. Linear mixed models and post-hoc tests were utilized for data analyses.

RESULTS

Altogether 33 PD patients completed the study (20 in the real stimulation group and 13 in the sham stimulation group). Linear mixed models revealed significant effects of time (F(3, 88.1) = 22.7, p < 0.001) and time-by-group interactions: F(3, 88.0) = 2.8, p = 0.040) for the Phonetics score. Real as compared to sham stimulation led to activation increases in the orofacial sensorimotor cortex and caudate nucleus and to increased intrinsic connectivity of these regions with the stimulated area.

CONCLUSIONS

This is the first study to show the long-term treatment effects of non-invasive brain stimulation for hypokinetic dysarthria in PD. Neural mechanisms of the changes are discussed.

Effects of repetitive transcranial magnetic stimulation (rTMS) on aphasia in stroke patients: A systematic review and meta-analysis

OBJECTIVE

To evaluate the effects and safety of repetitive transcranial magnetic stimulation (rTMS) on aphasia in stroke patients.

METHODS

We searched databases from inception to January 28, 2021. Randomized control trials investigating the effects and safety of rTMS for aphasia patients after stroke were included. Study screening, data extraction, and risk of bias assessment were performed independently by two reviewers. Meta-analysis was conducted with Review Manager 5.3 software. The quality of the evidence was assessed by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

RESULTS

Twenty-eight studies with 1287 patients were included. All studies were assessed at low or unclear risk of bias in one or more domains. The meta-analysis exhibited rTMS was better than sham rTMS and conventional rehabilitation in language recovery. Low-frequency rTMS showed greater improvement in language recovery except for comprehension than sham rTMS. Low-frequency and bilateral rTMS were superior to conventional rehabilitation in language recovery. High-frequency rTMS was no better than sham rTMS and conventional rehabilitation for improving aphasia. The rTMS had better effects in naming, comprehension and aphasia quotient at 20 sessions. Eleven studies reported rTMS was safe for aphasia patients after stroke. The quality of evidence for all outcomes was low or very low, and publication bias may exist.

CONCLUSIONS

rTMS may be relatively effective and safe for aphasia patients after stroke. However, these findings should be treated with caution due to high heterogeneity and potential biases.

Support vector machine based aphasia classification of transcranial magnetic stimulation language mapping in brain tumor patients

Repetitive TMS (rTMS) allows for non-invasive and transient disruption of local neuronal functioning. We used machine learning approaches to assess whether brain tumor patients can be accurately classified into aphasic and non-aphasic groups using their rTMS language mapping results as input features. Given that each tumor affects the subject-specific language networks differently, resulting in heterogenous rTMS functional mappings, we propose the use of machine learning strategies to classify potential patterns of rTMS language mapping results. We retrospectively included 90 patients with left perisylvian world health organization (WHO) grade II-IV gliomas that underwent presurgical navigated rTMS language mapping. Within our cohort, 29 of 90 (32.2%) patients suffered from at least mild aphasia as shown in the Aachen Aphasia Test based Berlin Aphasia Score (BAS). After spatial normalization to MNI 152 of all rTMS spots, we calculated the error rate (ER) in each stimulated cortical area (28 regions of interest, ROI) by automated anatomical labeling parcellation (AAL3) and IIT. We used a support vector machine (SVM) to classify significant areas in relation to aphasia. After feeding the ROIs into the SVM model, it revealed that in addition to age (w = 2.98), the ERs of the left supramarginal gyrus (w = 3.64), left inferior parietal gyrus (w = 2.28) and right pars triangularis (w = 1.34) contributed more than other features to the model. The model's sensitivity was 86.2%, the specificity was 82.0%, the overall accuracy was 85.5% and the AUC was 89.3%. Our results demonstrate an increased vulnerability of right inferior pars triangularis to rTMS in aphasic patients due to left perisylvian gliomas. This finding points towards a functional relevant involvement of the right pars triangularis in response to aphasia. The tumor location feature, specified by calculating overlaps with white and grey matter atlases, did not affect the SVM model. The left supramarginal gyrus as a feature improved our SVM model the most. Additionally, our results could point towards a decreasing potential for neuroplasticity with age.

Low-Frequency Repetitive Transcranial Magnetic Stimulation in Patients With Poststroke Aphasia: Systematic Review and Meta-Analysis of Its Effect Upon Communication

Objective The aim of the study was to investigate the effectiveness and safety of low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) in patients with poststroke aphasia. Method We comprehensively searched for eligible studies from 11 electronic medical databases from their inception to February 20, 2019. Randomized controlled trials reporting the effectiveness of LF-rTMS for patients with poststroke aphasia were included. The primary outcome was language ability. The secondary outcomes were functional communication and adverse events. The methodological quality of the randomized controlled trials was evaluated by the Cochrane Back Review Group Risk of Bias Assessment Criteria. Results Of the 567 records retrieved, 18 studies with a total of 536 participants were included. All the included studies were of relatively acceptable methodological quality. All studies but one used LF-rTMS + speech and language therapy (SLT), not LF-rTMS alone. The meta-analysis showed that LF-rTMS had beneficial effects for patients with aphasia after a stroke in terms of naming, repetition, comprehension, written language, and functional communication. The subgroup analyses of language performance showed positive effects of LF-rTMS among stroke patients with chronic aphasia and acute aphasia. LF-rTMS + SLT had effects on language performance that were superior to the sham rTMS + SLT and SLT alone. A shorter LF-rTMS duration benefited language performance more than a longer duration. Additionally, 20 min of LF-rTMS per session produced a positive effect on language ability for patients with aphasia after a stroke. No adverse events were reported. Conclusions LF-rTMS + SLT is an effective and safe method for patients with poststroke aphasia to improve their language performance. Additionally, the most commonly used LF-rTMS protocol for patients with aphasia after a stroke was 90% of the resting motor threshold 20 min per day, 5 days per week, for 2 weeks.

Funktionserholung nach Schlaganfall und die therapeutische Rolle der nicht-invasiven Hirnstimulation

Im Bereich der non-invasiven Hirnstimulation stellen die transkranielle Magnetstimulation (engl. transcranial magnetic stimulation, TMS) sowie die transkranielle Gleichstromstimulation (engl. transcranial direct current stimulation, tDCS) bis heute die wichtigsten Techniken zur Modulation kortikaler Erregbarkeit dar. Beide Verfahren induzieren Nacheffekte, welche die Zeit der reinen Stimulation überdauern, und ebnen damit den Weg für ihren therapeutischen Einsatz beim Schlaganfall. In diesem Übersichtsartikel diskutieren wir die aktuelle Datenlage TMS- und tDCS-vermittelter Therapien für die häufigsten schlaganfallbedingten Defizite wie Hemiparese, Aphasie und Neglect. Darüber hinaus adressieren wir mögliche Einschränkungen der gegenwärtigen Ansätze und zeigen Ansatzpunkte auf, um Neuromodulation nach Schlaganfall effektiver zu gestalten und damit das Outcome der Patienten zu verbessern.

Development and application of a Chinese Version of the Language Screening Test (CLAST) in post-stroke patients

Aphasia shows high incidence in stroke patients and seriously impairs language comprehension, verbal communication, and social activities. Therefore, screening aphasic patients during the acute phase of stroke is crucial for language recovery and rehabilitation. The present study developed a Chinese version of the Language Screening Test (CLAST) and validated it in post-stroke patients.The CLAST was adapted from the Language Screening Test developed by Constance et al to incorporate Chinese cultural and linguistic specificities, and administered to 207 acute stroke patients and 89 stabilized aphasic or non-aphasic patients. Based on the Western Aphasia Battery (WAB) test, its reliability and validity were assessed. A cut-off for the CLAST in Chinese patients was determined by ROC curve analysis.The CLAST comprised 5 subtests and 15 items, including 2 subscores, namely expression (8 points, assessing naming, repetition, and automatic speech) and receptive (7 points maximum, evaluating picture recognition, and verbal instructions) indexes. Analysis of the alternate-form reliability of the questionnaire showed a retest correlation coefficient of 0.945 (P < .001). Intraclass correlation coefficients of three rating teams were >0.98 (P < .001). Internal consistency analysis showed a Cronbach's alpha coefficient of 0.909 (P < .001). The non-aphasia group showed higher scores than the aphasia group (14.2 ± 1.3 vs 10.6 ± 3.8) (P < .01). The questionnaire showed good construct validity by factor analysis. ROC curve analysis showed high sensitivity and specificity for the CLAST, with a cut-off of 13.5.The CLAST is suitable for Chinese post-stroke patients during the acute phase, with high reliability, validity, sensitivity, and specificity.

Effects of repetitive transcranial magnetic stimulation with different frequencies on post-stroke aphasia: A PRISMA-compliant meta-analysis

BACKGROUNDS

Previous studies indicated inconsistent results for the treatment effect of repetitive transcranial magnetic stimulation (rTMS) on post-stroke aphasics. The study conducted a meta-analysis to evaluate whether the rTMS with different frequencies demonstrated any effect in patients with post-stroke aphasia.

METHODS

Electronic databases (PubMed, Web of Science, Medline, EMBASE, and Google Scholar) were searched for articles published before July 2019. Statistical analyses were made using STATA 12.0 software. Standard mean difference (SMD) with 95% confidence intervals (CI) were calculated for the treatment effect of rTMS on post-stroke aphasia.

RESULTS

Meta-analysis indicated significant treatment effects on naming of rTMS in post-stroke aphasics (SMD 0.76, 95%CI 0.16 to 1.36, I = 76.9%, P < .001). Subgroup analyses showed significant treatment effects on naming of low frequency (LF)-rTMS (SMD 0.40, 95%CI 0.10 to 0.69, I = 0.0%, P = .671). However, the changes in repetition and comprehension following stimulation were not significant.

CONCLUSIONS

In conclusion, we provide preliminary evidence that both LF-rTMS and high-frequency-rTMS might be relatively effective and safe treatment for post-stroke aphasics. However, LF-rTMS mainly plays a short-term role in subacute post-stroke aphasics. Longer-term and large-scale studies are essential to explore the effect of rTMS with different frequencies on post-stroke aphasia.

Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS): An update (2014-2018)

A group of European experts reappraised the guidelines on the therapeutic efficacy of repetitive transcranial magnetic stimulation (rTMS) previously published in 2014 [Lefaucheur et al., Clin Neurophysiol 2014;125:2150-206]. These updated recommendations take into account all rTMS publications, including data prior to 2014, as well as currently reviewed literature until the end of 2018. Level A evidence (definite efficacy) was reached for: high-frequency (HF) rTMS of the primary motor cortex (M1) contralateral to the painful side for neuropathic pain; HF-rTMS of the left dorsolateral prefrontal cortex (DLPFC) using a figure-of-8 or a H1-coil for depression; low-frequency (LF) rTMS of contralesional M1 for hand motor recovery in the post-acute stage of stroke. Level B evidence (probable efficacy) was reached for: HF-rTMS of the left M1 or DLPFC for improving quality of life or pain, respectively, in fibromyalgia; HF-rTMS of bilateral M1 regions or the left DLPFC for improving motor impairment or depression, respectively, in Parkinson's disease; HF-rTMS of ipsilesional M1 for promoting motor recovery at the post-acute stage of stroke; intermittent theta burst stimulation targeted to the leg motor cortex for lower limb spasticity in multiple sclerosis; HF-rTMS of the right DLPFC in posttraumatic stress disorder; LF-rTMS of the right inferior frontal gyrus in chronic post-stroke non-fluent aphasia; LF-rTMS of the right DLPFC in depression; and bihemispheric stimulation of the DLPFC combining right-sided LF-rTMS (or continuous theta burst stimulation) and left-sided HF-rTMS (or intermittent theta burst stimulation) in depression. Level A/B evidence is not reached concerning efficacy of rTMS in any other condition. The current recommendations are based on the differences reached in therapeutic efficacy of real vs. sham rTMS protocols, replicated in a sufficient number of independent studies. This does not mean that the benefit produced by rTMS inevitably reaches a level of clinical relevance.

The Effect of rTMS over the Different Targets on Language Recovery in Stroke Patients with Global Aphasia: A Randomized Sham-Controlled Study

Objective

To evaluate and compare the effects of repetitive transcranial magnetic stimulation (rTMS) over the right pars triangularis of the posterior inferior frontal gyrus (pIFG) and the right posterior superior temporal gyrus (pSMG) in global aphasia following subacute stroke.

Methods

Fifty-four patients with subacute poststroke global aphasia were randomized to 15-day protocols of 20-minute inhibitory 1 Hz rTMS over either the right triangular part of the pIFG (the rTMS-b group) or the right pSTG (the rTMS-w group) or to sham stimulation, followed by 30 minutes of speech and language therapy. Language outcomes were assessed by aphasia quotient (AQ) scores obtained from the Chinese version of the Western Aphasia Battery (WAB) at baseline and immediately after 3 weeks (15 days) of experimental treatment.

Results

Forty-five patients completed the entire study. The primary outcome measures include the changes in WAB-AQ score, spontaneous speech, auditory comprehension, and repetition. These measures indicated significant main effect between the baseline of the rTMS-w, rTMS-b, and sham groups and immediately after stimulation (P<0.05). Compared with the sham group, the increases were significant for auditory comprehension, repetition, and AQ in the rTMS-w group (P<0.05), whereas the changes in repetition, spontaneous speech, and AQ tended to be higher in the rTMS-b group (P<0.05).

Conclusions

Inhibitory rTMS targeting the right pIFG and pSTG can be an effective treatment for subacute stroke patients with global aphasia. The effect of rTMS may depend on the stimulation site. Low-frequency rTMS inhibited the right pSTG and significantly improved language recovery in terms of auditory comprehension and repetition, whereas LF-rTMS inhibited the right pIFG, leading to apparent changes in spontaneous speech and repetition.

Continuous theta burst stimulation over right pars triangularis facilitates naming abilities in chronic post-stroke aphasia by enhancing phonological access

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has been used experimentally to facilitate naming abilities in individuals with chronic post-stroke aphasia. However, little is known about how rTMS confers clinical improvement, hampering its therapeutic value. The present study investigated the characteristics of naming failure that improve following administration of continuous theta burst stimulation (cTBS)-an inhibitory form of rTMS-to the right pars triangularis (rPTr) in persons with chronic aphasia.

METHODS

Eleven participants with chronic aphasia following left hemisphere stroke named pictures prior to and immediately following cTBS of the rPTr and a control site (vertex) in separate sessions. Prior to stimulation, we obtained two baseline measurements of picture naming ability to determine the extent and type (i.e., phonological vs. semantic) of naming impairment. Items presented for naming during stimulation were those that were named incorrectly in one or both of the baseline sessions (i.e., inconsistent vs. wrong items, respectively). Analyses assessed whether cTBS effects differed depending on the severity and/or type of naming impairment.

RESULTS

Relative to vertex, cTBS of the rPTr improved naming of inconsistent, but not wrong, items for individuals with more severe baseline naming impairment. Critically, baseline phonological but not semantic naming impairment severity marginally correlated with improved accuracy overall, and significantly correlated with decreased phonological errors following rPTr stimulation.

CONCLUSION

CTBS of the rPTr enhances naming by facilitating phonological access during word retrieval, indicating that individuals whose naming impairment is localized to this stage of processing may be most likely to benefit from this rTMS approach.

Neuronavigated theta burst stimulation for chronic aphasia: two exploratory case studies

The present study reports the findings of a 10-day neuronavigated continuous theta burst stimulation (cTBS) over the right pars triangularis for two individuals with chronic aphasia after a single left hemispheric stroke. Baseline language and quality of life measures were collected prior to the treatment study, post-treatment and at 3-month follow up. Therapy was tolerated well by both participants and no side effects were noticed during and after treatment. Results from one individual showed potential for positive change in performance in comprehension and expressive language both post-treatment and at the follow-up stage. Also, a trend towards improvement post-treatment was noticed in discourse and sentence productivity, and grammatical accuracy. In the follow up stage, grammatical accuracy showed a trend towards improvement; discourse productivity decreased and; sentence productivity skills showed mixed results. Results from the other participant showed potential for positive change in comprehension post-treatment, that was maintained at the follow-up stage. However, a decline in expressive language post-treatment and at follow-up, stronger post-treatment, was noticed. Regarding quality of life measurements, participant one appeared to have improved as his performance increased in the overall, physical and communication domains, but decreased slightly in the psychosocial domain. The second participant improved in the physical and communication domains and declined overall and in the psychosocial domains. Findings from this study indicate that cTBS over the right pars triangularis may have the potential to improve various language skills in patients suffering from chronic aphasia post-stroke. However, the potential benefits of this fast, non-invasive brain stimulation protocol on improvement of language abilities post-stroke need further exploration.

The effect of low-frequency repetitive transcranial magnetic stimulation (rTMS) on the treatment of aphasia caused by cerebrovascular accident (CVA)

Background: Aphasia is a common outcome of Cerebrovascular Accident (CVA) in which clinical interventions have limited effectiveness. Some evidence suggests that noninvasive stimulation of the brain can have beneficial effects in the treatment of CVA induced aphasia. In patients with motor aphasia, repetitive Transcranial Magnetic Stimulation (rTMS) is used to facilitate long-term improvement in speech ability. Since identifying effective methods for treating CVA induced aphasia can be very important in subsequent decision-making and treatment interventions, the objective of this study was to evaluate the effect of low-frequency TMS in Broca’s area in the right hemisphere on the treatment of CVA induced motor aphasia.

Methods: This clinical trial enrolled 24 patients with a clinical diagnosis of motor aphasia caused by CVA using convenient sampling. In this study, the effect of stimulation of Broca’s area in the right hemisphere was examined by low-frequency rTMS (one Hz) on aphasia caused by CVA. To conduct verbal fluency test in patients, their correct responses to the selected images before and after rTMS during a certain time were recorded and compared by non-parametric Wilcoxon test using SPSS16 and the significance level was considered <0.05. Registration ID of this research in IRCT is IRCT2014052417814N1.

Results: The study findings suggested a significant difference between Wilcoxon test results of patients before and after rTMS (z= -4.401), and it was found that using low-frequency rTMS in the right hemisphere was effective on improving dysarthria in the study population with 95 percent confidence interval (p<0.001).

Conclusion: According to the findings, low-frequency rTMS has the potential to be considered as a treatment for patients with nonfluent aphasia caused by CVA.

Imaging effects related to language improvements by rTMS

The functional deficit after a focal brain lesion is determined by the localization and the extent of the tissue damage. Since destroyed tissue usually cannot be replaced in the adult human brain, improvement or recovery of neurological deficits can be achieved only by reactivation of functionally disturbed but morphologically preserved areas or by recruitment of alternative pathways within the functional network. The visualization of disturbed interaction in functional networks and of their reorganization in the recovery after focal brain damage is the domain of functional imaging modalities such as positron emission tomography (PET). Longitudinal assessments at rest and during activation tasks during the early and later periods following a stroke can demonstrate recruitment and compensatory mechanisms in the functional network responsible for complete or partial recovery of disturbed functions. Imaging studies have shown that improvements after focal cortical injury are represented over larger cortical territories. It has also been shown that the unaffected hemisphere in some instances actually inhibits the recovery of ipsilateral functional networks and this effect of transcallosal inhibition can be reduced by non-invasive brain stimutation. Non-invasive brain stimulation (NIBS) can modulate the excitability and activity of targeted cortical regions and thereby alter the interaction within pathologically affected functional networks; this kind of intervention might promote the adaptive cortical reorganization of functional networks after stroke. In poststroke aphasia several studies attempted to restore perilesional neuronal activity in the injured left inferior frontal gyrus by applying excitatory high frequency repetitive transcranial magnetic stimulation (rTMS) or intermittent theta burst stimulation (iTBS) or anodal transcranial direct current stimulation (tDCS), but most NIBS studies in poststroke aphasia employed inhibitory low frequency rTMS for stimulation of the contralesional pars triangularis of the right inferior frontal gyrus (BA 45) in order to reduce right hemisphere hyperactivity and transcallosal inhibition on the left Broca's area. While most studies reported single cases or small case series with chronic poststroke aphasia without any control condition, only a few controlled studies including sham stimulation were performed in chronic stage after stroke. In one controlled randomized study changes in PET activation pattern in the subacute course were related to the clinical improvement. In this "proof-of-principle" study the shift of the activation pattern to the dominant hemisphere induced by inhibitory rTMS over the right inferior frontal gyrus could be demonstrated in the PET activation studies and correlated to improved performance in aphasia tests. NIBS might be a treatment strategy which could improve the effect of other rehabilitative efforts.

The pathophysiology of post-stroke aphasia: A network approach

BACKGROUND

Post-stroke aphasia syndromes as a clinical entity arise from the disruption of brain networks specialized in language production and comprehension due to permanent focal ischemia. This approach to post-stroke aphasia is based on two pathophysiological concepts: 1) Understanding language processing in terms of distributed networks rather than language centers and 2) understanding the molecular pathophysiology of ischemic brain injury as a dynamic process beyond the direct destruction of network centers and their connections. While considerable progress has been made in the past 10 years to develop such models on a systems as well as a molecular level, the influence of these approaches on understanding and treating clinical aphasia syndromes has been limited.

OBJECTIVE & METHODS

In this article, we review current pathophysiological concepts of ischemic brain injury, their relationship to altered information processing in language networks after ischemic stroke and how these mechanisms may be influenced therapeutically to improve treatment of post-stroke aphasia.

CONCLUSION

Understanding the pathophysiological mechanism of post-stroke aphasia on a neurophysiological systems level as well as on the molecular level becomes more and more important for aphasia treatment, as the field moves from standardized therapies towards more targeted individualized treatment strategies comprising behavioural therapies as well as non-invasive brain stimulation (NIBS).

The effect of low-frequency repetitive transcranial magnetic stimulation (rTMS) on the treatment of aphasia caused by cerebrovascular accident (CVA)

Background: Aphasia is a common outcome of Cerebrovascular Accident (CVA) in which clinical interventions have limited effectiveness. Some evidence suggests that noninvasive stimulation of the brain can have beneficial effects in the treatment of CVA induced aphasia. In patients with motor aphasia, repetitive Transcranial Magnetic Stimulation (rTMS) is used to facilitate long-term improvement in speech ability. Since identifying effective methods for treating CVA induced aphasia can be very important in subsequent decision-making and treatment interventions, the objective of this study was to evaluate the effect of low-frequency TMS in Broca’s area in the right hemisphere on the treatment of CVA induced motor aphasia.

Methods: This clinical trial enrolled 24 patients with a clinical diagnosis of motor aphasia caused by CVA using convenient sampling. In this study, the effect of stimulation of Broca’s area in the right hemisphere was examined by low-frequency rTMS (one Hz) on aphasia caused by CVA. To conduct verbal fluency test in patients, their correct responses to the selected images before and after rTMS during a certain time were recorded and compared by non-parametric Wilcoxon test using SPSS16 and the significance level was considered <0.05. Registration ID of this research in IRCT is IRCT2014052417814N1.

Results: The study findings suggested a significant difference between Wilcoxon test results of patients before and after rTMS (z= -4.401), and it was found that using low-frequency rTMS in the right hemisphere was effective on improving dysarthria in the study population with 95 percent confidence interval (p<0.001).

Conclusion: According to the findings, low-frequency rTMS has the potential to be considered as a treatment for patients with nonfluent aphasia caused by CVA.

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.

Neuroimaging of stroke recovery from aphasia - Insights into plasticity of the human language network

The role of left and right hemisphere brain regions in language recovery after stroke-induced aphasia remains controversial. Here, we summarize how neuroimaging studies increase the current understanding of functional interactions, reorganization and plasticity in the language network. We first discuss the temporal dynamics across the time course of language recovery, with a main focus on longitudinal studies from the acute to the chronic phase after stroke. These studies show that the functional contribution of perilesional and spared left hemisphere as well as contralesional right hemisphere regions to language recovery changes over time. The second section introduces critical variables and recent advances on early prediction of subsequent outcome. In the third section, we outline how multi-method approaches that combine neuroimaging techniques with non-invasive brain stimulation elucidate mechanisms of plasticity and reorganization in the language network. These approaches provide novel insights into general mechanisms of plasticity in the language network and might ultimately support recovery processes during speech and language therapy. Finally, the neurobiological correlates of therapy-induced plasticity are discussed. We argue that future studies should integrate individualized approaches that might vary the combination of language therapy with specific non-invasive brain stimulation protocols across the time course of recovery. The way forward will include the combination of such approaches with large data sets obtained from multicentre studies.

The Use of Repetitive Transcranial Magnetic Stimulation for Stroke Rehabilitation: A Systematic Review

OBJECTIVES

Stroke is a leading cause of disability. Alternative and more effective techniques for stroke rehabilitation have been sought to overcome limitations of conventional therapies. Repetitive transcranial magnetic stimulation (rTMS) arises as a promising tool in this context. This systematic review aims to provide a state of the art on the application of rTMS in stroke patients and to assess its effectiveness in clinical rehabilitation of motor function.

METHODS

Studies included in this review were identified by searching PubMed and ISI Web of Science. The search terms were (rTMS OR "repetitive transcranial magnetic stimulation") AND (stroke OR "cerebrovascular accident" OR CVA) AND (rehab OR rehabilitation OR recover*). The retrieved records were assessed for eligibility and the most relevant features extracted to a summary table.

RESULTS

Seventy out of 691 records were deemed eligible, according to the selection criteria. The majority of the articles report rTMS showing potential in improving motor function, although some negative reports, all from randomized controlled trials, contradict this claim. Future studies are needed because there is a possibility that a bias for non-publication of negative results may be present.

CONCLUSIONS

rTMS has been shown to be a promising tool for stroke rehabilitation, in spite of the lack of standard operational procedures and harmonization. Efforts should be devoted to provide a greater understanding of the underlying mechanisms and protocol standardization.

A Framework for Combining rTMS with Behavioral Therapy

Upon its inception, repetitive transcranial magnetic stimulation (rTMS) was delivered at rest, without regard to the potential impact of activity occurring during or around the time of stimulation. rTMS was considered an experimental intervention imposed on the brain; therefore, the myriad features that might suppress or enhance its desired effects had not yet been explored. The field of rTMS has since grown substantially and therapeutic benefits have been reported, albeit with modest and inconsistent improvements. Work in this field accelerated following approval of a psychiatric application (depression), and it is now expanding to other applications and disciplines. In the last decade, experimental enquiry has sought new ways to improve the therapeutic benefits of rTMS, intended to enhance underlying brain reorganization and functional recovery by combining it with behavioral therapy. This concept is appealing, but poorly defined and requires clarity. We provide an overview of how combined rTMS and behavioral therapy has been delineated in the literature, highlighting the diversity of approaches. We outline a framework for study design and reporting such that the effects of this emerging method can be better understood.