Advances and Innovations in Aphasia Treatment Trials

Non-invasive brain stimulation in the treatment of post-stroke aphasia: a scoping review

PURPOSE

Aphasia is an acquired language impairment that commonly results from stroke. Non-invasive brain stimulation (NIBS) might accelerate aphasia recovery trajectories and has seen mounting popularity in recent aphasia rehabilitation research. The present review aimed to: (1) summarise all existing literature on NIBS as a post-stroke aphasia treatment; and (2) provide recommendations for future NIBS-aphasia research.

MATERIALS AND METHODS

Databases for published and grey literature were searched using scoping review methodology. 278 journal articles, conference abstracts/posters, and books, and 38 items of grey literature, were included for analysis.

RESULTS

Quantitative analysis revealed that ipsilesional anodal transcranial direct current stimulation and contralesional 1-Hz repetitive transcranial magnetic stimulation were the most widely used forms of NIBS, while qualitative analysis identified four key themes including: the roles of the hemispheres in aphasia recovery and their relationship with NIBS; heterogeneity of individuals but homogeneity of subpopulations; individualisation of stimulation parameters; and much remains under-explored in the NIBS-aphasia literature.

CONCLUSIONS

Taken together, these results highlighted systemic challenges across the field such as small sample sizes, inter-individual variability, lack of protocol optimisation/standardisation, and inadequate focus on aphasiology. Four key recommendations are outlined herein to guide future research and refine NIBS methods for post-stroke aphasia treatment.

Effects of repetitive transcranial magnetic stimulation combined with music therapy in non-fluent aphasia after stroke: A randomised controlled study

BACKGROUND

Although existing studies have shown that both repetitive transcranial magnetic stimulation (rTMS) and music therapy have advantages in the treatment of non-fluent aphasia, the efficacy of the combination of these two methods remains to be investigated.

AIMS

To investigate the clinical efficacy of low-frequency rTMS combined with music therapy on language function and depression in patients with non-fluent aphasia after stroke.

METHODS & PROCEDURES

A single-blind parallel randomised controlled trial was conducted. Sixty patients (mean duration = 93.78 days) with non-fluent aphasia after stroke were randomly divided into a traditional therapy group (n = 20), a music therapy group (n = 20) and a combined therapy group (n = 20, 1 Hz). The language function and depression were evaluated before and 3 weeks after treatment with the Chinese version of the Western Aphasia Battery scale, Boston Diagnostic Aphasia Examination scale and Stroke Aphasic Depression Questionnaire Hospital Version scale.

OUTCOMES & RESULTS

The combined therapy group was significantly better in all outcomes than the traditional therapy group and was significantly better in depression than the music therapy group. The music therapy group was significantly better in repetition and depression than the traditional therapy group. Language improvement was positively correlated with depression improvement. For adverse events, only two patients in the combined therapy group showed slight dizziness during rTMS treatment and their symptoms improved after rest.

CONCLUSIONS & IMPLICATIONS

Our preliminary randomised controlled study indicates that low-frequency rTMS combined with music therapy is feasible and safe in improving language function and depression in non-fluent aphasia patients after stroke.

WHAT THIS PAPER ADDS

What is already known on this subject Repetitive transcranial magnetic stimulation (rTMS) and music therapy respectively have advantages in the treatment of non-fluent aphasia after stroke, but whether the combination of the two methods is more effective is still unknown. What this paper adds to the existing knowledge This is one of the first randomised control trials to investigate whether the clinical efficacy of low-frequency rTMS combined music therapy for non-fluent aphasia is better. The findings show that low-frequency rTMS combined music therapy is superior to traditional therapy in spontaneous speech, auditory comprehension, repetition, naming, aphasia quotient, functional language level and depression, and superior to music therapy in depression, while music therapy is superior to traditional therapy in repetition and depression. What are the potential or actual clinical implications of this work? Low-frequency rTMS combined music therapy may be a better method for treatment of non-fluent aphasia.

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.

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.

Noninvasive brain stimulation for cognitive rehabilitation following traumatic brain injury: A systematic review

Traumatic brain injury (TBI) can cause numerous cognitive deficits. These deficits are associated with disability and reduction in quality of life. Noninvasive brain stimulation (NIBS) provides excitatory or inhibitory stimuli to the cerebral cortex. This review aimed to examine the effectiveness of NIBS (i.e., rTMS and tDCS) on cognitive functions in patients with TBI. PubMed, SCOPUS, PEDro, CINAHL, MEDLINE, REHABDATA, and Web of Science were searched from inception to May 2021. The risk of bias in the randomized controlled trials was assessed using the Cochrane Collaboration's instrument. The Physiotherapy Evidence Database (PEDro) scale was applied to evaluate the risk of bias in the non-randomized controlled trials. Ten studies met our inclusion criteria. Six studies used repetitive Transcranial Magnetic Stimulation (rTMS), and four used transcranial Direct Current Stimulation (tDCS) as cognitive rehabilitation interventions. The results showed heterogenous evidence for the effects of rTMS and tDCS on cognitive function outcomes in individuals with TBI. The evidence for the effects of NIBS on cognition following TBI was limited. TDCS and rTMS are safe and well-tolerated interventions post-TBI. The optimal stimulation sites and stimulation parameters remain unknown. Combining NIBS with traditional rehabilitation interventions may contribute to greater enhancements in cognitive functions post-TBI.

Cerebral perfusion in post-stroke aphasia and its relationship to residual language abilities

Stroke alters blood flow to the brain resulting in damaged tissue and cell death. Moreover, the disruption of cerebral blood flow (perfusion) can be observed in areas surrounding and distal to the lesion. These structurally preserved but suboptimally perfused regions may also affect recovery. Thus, to better understand aphasia recovery, the relationship between cerebral perfusion and language needs to be systematically examined. In the current study, we aimed to evaluate (i) how stroke affects perfusion outside of lesioned areas in chronic aphasia and (ii) how perfusion in specific cortical areas and perilesional tissue relates to language outcomes in aphasia. We analysed perfusion data from a large sample of participants with chronic aphasia due to left hemisphere stroke (n = 43) and age-matched healthy controls (n = 25). We used anatomically defined regions of interest that covered the frontal, parietal, and temporal areas of the perisylvian cortex in both hemispheres, areas typically known to support language, along with several control regions not implicated in language processing. For the aphasia group, we also looked at three regions of interest in the perilesional tissue. We compared perfusion levels between the two groups and investigated the relationship between perfusion levels and language subtest scores while controlling for demographic and lesion variables. First, we observed that perfusion levels outside the lesioned areas were significantly reduced in frontal and parietal regions in the left hemisphere in people with aphasia compared to the control group, while no differences were observed for the right hemisphere regions. Second, we found that perfusion in the left temporal lobe (and most strongly in the posterior part of both superior and middle temporal gyri) and inferior parietal areas (supramarginal gyrus) was significantly related to residual expressive and receptive language abilities. In contrast, perfusion in the frontal regions did not show such a relationship; no relationship with language was also observed for perfusion levels in control areas and all right hemisphere regions. Third, perilesional perfusion was only marginally related to language production abilities. Cumulatively, the current findings demonstrate that blood flow is reduced beyond the lesion site in chronic aphasia and that hypoperfused neural tissue in critical temporoparietal language areas has a negative impact on behavioural outcomes. These results, using perfusion imaging, underscore the critical and general role that left hemisphere posterior temporal regions play in various expressive and receptive language abilities. Overall, the study highlights the importance of exploring perfusion measures in stroke.

Understanding recovery of language after stroke: insights from neurovascular MRI studies

Stroke causes a disruption in blood flow to the brain that can lead to profound language impairments. Understanding the mechanisms of language recovery after stroke is crucial for the prognosis and effective rehabilitation of people with aphasia. While the role of injured brain structures and disruptions in functional connectivity have been extensively explored, the relationship between neurovascular measures and language recovery in both early and later stages has not received sufficient attention in the field. Fully functioning healthy brain tissue requires oxygen and nutrients to be delivered promptly via its blood supply. Persistent decreases in blood flow after a stroke to the remaining non-lesioned tissue have been shown to contribute to poor language recovery. The goal of the current paper is to critically examine stroke studies looking at the relationship between different neurovascular measures and language deficits and mechanisms of language recovery via changes in neurovascular metrics. Measures of perfusion or cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) provide complementary approaches to understanding neurovascular mechanisms post stroke by capturing both cerebral metabolic demands and mechanical vascular properties. While CBF measures indicate the amount of blood delivered to a certain region and serve as a proxy for metabolic demands of that area, CVR indices reflect the ability of the vasculature to recruit blood flow in response to a shortage of oxygen, such as when one is holding their breath. Increases in CBF during recovery beyond the site of the lesion have been shown to promote language gains. Similarly, CVR changes, when collateral vessels are recruited to help reorganize the flow of blood in hypoperfused regions, have been related to functional recovery post stroke. In the current review, we highlight the main findings in the literature investigating neurovascular changes in stroke recovery with a particular emphasis on how language abilities can be affected by changes in CBF and CVR. We conclude by summarizing existing methodological challenges and knowledge gaps that need to be addressed in future work in this area, outlining a promising avenue of research.

Predicting Outcomes of Language Rehabilitation: Prognostic Factors for Immediate and Long-Term Outcomes After Aphasia Therapy

BACKGROUND

Aphasia therapy is an effective approach to improve language function in chronic aphasia. However, it remains unclear what prognostic factors facilitate therapy response at the individual level. Here, we utilized data from the POLAR (Predicting Outcomes of Language Rehabilitation in Aphasia) trial to (a) determine therapy-induced change in confrontation naming and long-term maintenance of naming gains and (b) examine the extent to which aphasia severity, age, education, time postonset, and cognitive reserve predict naming gains at 1 week, 1 month, and 6 months posttherapy.

METHOD

A total of 107 participants with chronic (≥ 12 months poststroke) aphasia underwent extensive case history, cognitive-linguistic testing, and a neuroimaging workup prior to receiving 6 weeks of impairment-based language therapy. Therapy-induced change in naming performance (measured as raw change on the 175-item Philadelphia Naming Test [PNT]) was assessed 1 week after therapy and at follow-up time points 1 month and 6 months after therapy completion. Change in naming performance over time was evaluated using paired t tests, and linear mixed-effects models were constructed to examine the association between prognostic factors and therapy outcomes.

RESULTS

Naming performance was improved by 5.9 PNT items (Cohen's d = 0.56, p < .001) 1 week after therapy and by 6.4 (d = 0.66, p < .001) and 7.5 (d = 0.65, p < .001) PNT items at 1 month and 6 months after therapy completion, respectively. Aphasia severity emerged as the strongest predictor of naming improvement recovery across time points; mild (ß = 5.85-9.02) and moderate (ß = 9.65-11.54) impairment predicted better recovery than severe (ß = 1.31-3.37) and very severe (ß = 0.20-0.32) aphasia. Age was an emergent prognostic factor for recovery 1 month (ß = -0.14) and 6 months (ß = -0.20) after therapy, and time postonset (ß = -0.05) was associated with retention of naming gains at 6 months posttherapy.

CONCLUSIONS

These results suggest that therapy-induced naming improvement is predictable based on several easily measurable prognostic factors. Broadly speaking, these results suggest that prognostication procedures in aphasia therapy can be improved and indicate that personalization of therapy is a realistic goal in the near future.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.22141829.

Agrammatic output in non-fluent, including Broca's, aphasia as a rational behavior

Background

Speech of individuals with non-fluent, including Broca's, aphasia is often characterized as "agrammatic" because their output mostly consists of nouns and, to a lesser extent, verbs and lacks function words, like articles and prepositions, and correct morphological endings. Among the earliest accounts of agrammatic output in the early 1900s was the "economy of effort" idea whereby agrammatic output is construed as a way of coping with increases in the cost of language production. This idea resurfaced in the 1980s, but in general, the field of language research has largely focused on accounts of agrammatism that postulated core deficits in syntactic knowledge.

Aims

We here revisit the economy of effort hypothesis in light of increasing emphasis in cognitive science on rational and efficient behavior.

Main contribution

The critical idea is as follows: there is a cost per unit of linguistic output, and this cost is greater for patients with non-fluent aphasia. For a rational agent, this increase leads to shorter messages. Critically, the informative parts of the message should be preserved and the redundant ones (like the function words and inflectional markers) should be omitted. Although economy of effort is unlikely to provide a unifying account of agrammatic output in all patients-the relevant population is too heterogeneous and the empirical landscape too complex for any single-factor explanation-we argue that the idea of agrammatic output as a rational behavior was dismissed prematurely and appears to provide a plausible explanation for a large subset of the reported cases of expressive aphasia.

Conclusions

The rational account of expressive agrammatism should be evaluated more carefully and systematically. On the basic research side, pursuing this hypothesis may reveal how the human mind and brain optimize communicative efficiency in the presence of production difficulties. And on the applied side, this construal of expressive agrammatism emphasizes the strengths of some patients to flexibly adapt utterances in order to communicate in spite of grammatical difficulties; and focusing on these strengths may be more effective than trying to "fix" their grammar.

The efficacy and safety of acupuncture combined with language training for motor aphasia after stroke: study protocol for a multicenter randomized sham-controlled trial

BACKGROUND

Motor aphasia after stroke is a common and intractable complication of stroke. Acupuncture and language training may be an alternative and effective approach. However, the efficacy of acupuncture and language training for motor aphasia after stroke has not been confirmed. The main objectives of this trial are to evaluate the effectiveness and safety of acupuncture and low-intensity, low-dose language training in treating ischemic motor aphasia after stroke from 15 to 90 days.

METHODS

This is a multicenter randomized sham-controlled clinical trial. We will allocate 252 subjects aged between 45 and 75 years diagnosed with motor aphasia after stroke with an onset time ranging from 15 to 90 days into two groups randomly in a 1:1 ratio. Patients in the experimental group will be treated with "Xing-Nao Kai-Qiao" acupuncture therapy plus language training, and those in the control group will be treated with sham-acupoint (1 cun next to the acupoints) acupuncture therapy plus language training. All the patients will be given acupuncture and language training for 6 weeks, with a follow-up evaluation 6 weeks after the end of the treatment and 6 months after the onset time. The patients will mainly be evaluated using the Western Aphasia Battery and Chinese Functional Communication Profile, and the incidence of treatment-related adverse events at the 2nd, 4th, and 6th weeks of treatment will be recorded. The baseline characteristics of the patients will be summarized by group, the chi-squared test will be used to compare categorical variables, and repeated measures of analysis of variance or a linear mixed model will be applied to analyze the changes measured at different time points.

DISCUSSION

The present study is designed to investigate the effectiveness and safety of traditional acupuncture therapy and language training in ischemic motor aphasia after stroke and explore the correlation between the treatment time and clinical effect of acupuncture. We hope our results will help doctors understand and utilize acupuncture combined with language training.

TRIAL REGISTRATION

ChiCTR ChiCTR1900026740 . Registered on 20 October 2019.

Predictors of Therapy Response in Chronic Aphasia: Building a Foundation for Personalized Aphasia Therapy

Chronic aphasia, a devastating impairment of language, affects up to a third of stroke survivors. Speech and language therapy has consistently been shown to improve language function in prior clinical trials, but few clinicially applicable predictors of individual therapy response have been identified to date. Consequently, clinicians struggle substantially with prognostication in the clinical management of aphasia. A rising prevalence of aphasia, in particular in younger populations, has emphasized the increasing demand for a personalized approach to aphasia therapy, that is, therapy aimed at maximizing language recovery of each individual with reference to evidence-based clinical recommendations. In this narrative review, we discuss the current state of the literature with respect to commonly studied predictors of therapy response in aphasia. In particular, we focus our discussion on biographical, neuropsychological, and neurobiological predictors, and emphasize limitations of the literature, summarize consistent findings, and consider how the research field can better support the development of personalized aphasia therapy. In conclusion, a review of the literature indicates that future research efforts should aim to recruit larger samples of people with aphasia, including by establishing multisite aphasia research centers.

Transcranial Direct-Current Stimulation and Behavioral Training, a Promising Tool for a Tailor-Made Post-stroke Aphasia Rehabilitation: A Review

Aphasia is an acquired language disorder resulting from damage to portions of the brain which are responsible for language comprehension and formulation. This disorder can involve different levels of language processing with impairments in both oral and written comprehension and production. Over the last years, different rehabilitation and therapeutic interventions have been developed, especially non-invasive brain stimulation (NIBS) techniques. One of the most used NIBS techniques in aphasia rehabilitation is the Transcranial Direct-Current Stimulation (tDCS). It has been proven to be effective in promoting a successful recovery both in the short and the long term after a brain injury. The main strength of tDCS is its feasibility associated with relatively minor side effects, if safely and properly administered. TDCS requires two electrodes, an anode and a cathode, which are generally placed on the scalp. The electrode montage can be either unipolar or bipolar. The main aim of this review is to give an overview of the state of the art of tDCS for the treatment of aphasia. The studies described included patients with different types of language impairments, especially with non-fluent aphasia and in several cases anomia. The effects of tDCS are variable and depend on several factors, such as electrode size and montage, duration of the stimulation, current density and characteristics of the brain tissue underneath the electrodes. Generally, tDCS has led to promising results in rehabilitating patients with acquired aphasia, especially if combined with different language and communication therapies. The selection of the appropriate approach depends on the patients treated and their impaired language function. When used in combination with treatments such as Speech and Language Therapy, Constraint Induced Aphasia Therapy or Intensive Action Treatment, tDCS has generally promoted a better recovery of the impaired functions. In addition to these rehabilitation protocols, Action Observation Therapy, such as IMITAF, appeared to contribute to the reduction of post-stroke anomia. The potential of combining such techniques with tDCS would would therefore be a possibility for further improvement, also providing the clinician with a new action and intervention tool. The association of a tDCS protocol with a dedicated rehabilitation training would favor a generalized long-term improvement of the different components of language.

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.

Individualized response to semantic versus phonological aphasia therapies in stroke

Attempts to personalize aphasia treatment to the extent where it is possible to reliably predict individual response to a particular treatment have yielded inconclusive results. The current study aimed to (i) compare the effects of phonologically versus semantically focussed naming treatment and (ii) examine biographical and neuropsychological baseline factors predictive of response to each treatment. One hundred and four individuals with chronic post-stroke aphasia underwent 3 weeks of phonologically focussed treatment and 3 weeks of semantically focussed treatment in an unblinded cross-over design. A linear mixed-effects model was used to compare the effects of treatment type on proportional change in correct naming across groups. Correlational analysis and stepwise regression models were used to examine biographical and neuropsychological predictors of response to phonological and semantic treatment across all participants. Last, chi-square tests were used to explore the association between treatment response and phonological and semantic deficit profiles. Semantically focussed treatment was found to be more effective at the group-level, independently of treatment order (P = 0.041). Overall, milder speech and language impairment predicted good response to semantic treatment (r range: 0.256-0.373) across neuropsychological tasks. The Western Aphasia Battery-Revised Spontaneous Speech score emerged as the strongest predictor of semantic treatment response (R ² = 0.188). Severity of stroke symptoms emerged as the strongest predictor of phonological treatment response (R ² = 0.103). Participants who showed a good response to semantic treatment were more likely to present with fluent speech compared to poor responders (P = 0.005), whereas participants who showed a good response to phonological treatment were more likely to present with apraxia of speech (P = 0.020). These results suggest that semantic treatment may be more beneficial to the improvement of naming performance in aphasia than phonological treatment, at the group-level. In terms of personalized predictors, participants with relatively mild impairments and fluent speech responded better to semantic treatment, while phonological treatment benefitted participants with more severe impairments and apraxia of speech.

Novel Advances to Post-Stroke Aphasia Pharmacology and Rehabilitation

Aphasia is one of the most common clinical features of functional impairment after a stroke. Approximately 21–40% of stroke patients sustain permanent aphasia, which progressively worsens one’s quality of life and rehabilitation outcomes. Post-stroke aphasia treatment strategies include speech language therapies, cognitive neurorehabilitation, telerehabilitation, computer-based management, experimental pharmacotherapy, and physical medicine. This review focuses on current evidence of the effectiveness of impairment-based aphasia therapies and communication-based therapies (as well as the timing and optimal treatment intensities for these interventions). Moreover, we present specific interventions, such as constraint-induced aphasia therapy (CIAT) and melodic intonation therapy (MIT). Accumulated data suggest that using transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) is safe and can be used to modulate cortical excitability. Therefore, we review clinical studies that present TMS and tDCS as (possible) promising therapies in speech and language recovery, stimulating neuroplasticity. Several drugs have been used in aphasia pharmacotherapy, but evidence from clinical studies suggest that only nootropic agents, donepezil and memantine, may improve the prognosis of aphasia. This article is an overview on the current state of knowledge related to post-stroke aphasia pharmacology, rehabilitation, and future trends.

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.

Treatment of post-stroke aphasia: A narrative review for stroke neurologists

This review is intended to help physicians guide patients to optimal management of post-stroke aphasia. We review literature on post-stroke aphasia treatment, focusing on: (1) when and for whom language therapy is most effective, (2) the variety of approaches that can be effective for different individuals, and (3) the extent to which behavioral therapy might be augmented by non-invasive brain stimulation and/or medications.

The Effect of Non-Invasive Brain Stimulation (NIBS) on Executive Functioning, Attention and Memory in Rehabilitation Patients with Traumatic Brain Injury: A Systematic Review

In recent years, the potential of non-invasive brain stimulation (NIBS) for therapeutic effects on cognitive functions has been explored for populations with traumatic brain injury (TBI). However, there is no systematic NIBS review of TBI cognitive impairment with a focus on stimulation sites and stimulation parameters. The purpose of this study was to conduct a systematic review examining the effectiveness and safety of NIBS for cognitive impairment after a TBI. This study was prospectively registered with the PROSPERO database of systematic reviews (CRD42020183298). All English articles from the following databases were searched from inception up to 31 December 2020: Pubmed/MEDLINE, Scopus, CINAHL, Embase, PsycINFO and CENTRAL. Randomized and prospective controlled trials, including cross-over studies, were included for analysis. Studies with at least five individuals with TBI, whereby at least five sessions of NIBS were provided and used standardized neuropsychological measurement of cognition, were included. A total of five studies met eligibility criteria. Two studies used repetitive transcranial magnetic stimulation (rTMS) and three studies used transcranial direct current stimulation (tDCS). The pooled sample size was 44 individuals for rTMS and 91 for tDCS. Three of five studies combined cognitive training or additional therapy (computer assisted) with NIBS. Regarding rTMS, target symptoms included attention (n = 2), memory (n = 1), and executive function (n = 2); only one study showing significant improvement compared than control group with respect to attention. In tDCS studies, target symptoms included cognition (n = 2), attention (n = 3), memory (n = 3), working memory (WM) (n = 3), and executive function (n = 1); two of three studies showed significant improvement compared to the control group with respect to attention and memory. The evidence for NIBS effectiveness in rehabilitation of cognitive function in TBI is still in its infancy, more studies are needed. In all studies, dorsolateral prefrontal cortex (DLPFC) was selected as the stimulation site, along with the stimulation pattern promoting the activation of the left DLPFC. In some studies, there was a significant improvement compared to the control group, but neither rTMS nor tDCS had sufficient evidence of effectiveness. To the establishment of evidence we need the evaluation of brain activity at the stimulation site and related areas using neuroimaging on how NIBS acts on the neural network.

Evaluating the Long-Term Efficacy of Acupuncture Therapy for Subacute Poststroke Aphasia: Study Protocol for a Randomized, Blinded, Controlled, Multicentre Trial

Background

Poststroke aphasia (PSA) is a disabling condition that decreases the quality of life, and the duration of the disease harms the quality of life of PSA patients. Acupuncture has been widely employed for PSA. There is some evidence for the immediate treatment efficacy of acupuncture for PSA; however, long-term results after acupuncture may be poorer.

Methods

This is a multicentre, randomized, blinded, nonacupoint (NA) acupuncture controlled, multimodal neuroimaging clinical trial. A total of 48 subjects with subacute PSA will be randomly assigned to an acupoint group or an NA control group. The acupoint group will receive acupuncture with normal needling at DU20, EX-HN1, HT5, GB39, EX-HN12, EX-HN13, and CV23. The NA control group will receive acupuncture in locations not corresponding to acupuncture points as sham acupoints. Both groups will receive identical speech and language therapy thrice a week for four weeks. The primary outcome will be the change in the aphasia quotient (AQ) score measured by the Western Aphasia Battery (WAB) test during the 12th week after randomization. Participants will be blindly assessed at prerandomization (baseline) and 4 weeks, 12 weeks, and 24 weeks after randomization. The secondary outcomes include the Boston Diagnostic Aphasia Examination (BDAE) score, the Disease Prognosis Scale score for ischaemic stroke, etc. Magnetic resonance imaging (MRI) and electroencephalogram (EEG) will also be performed at 4-time intervals as secondary outcomes. All scores and image evaluations will be taken at the same point as the linguistic evaluation. The multilevel evaluation technique will be used to assess the long-term efficacy of acupuncture therapy. MRI scans and EEG will be used to assess acupuncture-related neuroplasticity changes. Discussion. The results from our trial will help to supply evidence for the long-term acupuncture effects for PSA over a long follow-up period. It will provide valuable information for future studies in the field of PSA treatment. The trial was registered at the Chinese Clinical Trial Registry on 16 March 2020 (ChiCTR2000030879).

The Effect of Non-Invasive Brain Stimulation (NIBS) on Attention and Memory Function in Stroke Rehabilitation Patients: A Systematic Review and Meta-Analysis

Background: In recent years, the potential of non-invasive brain stimulation (NIBS) for therapeutic effects on cognitive functions has been explored for populations with stroke. There are various NIBS methods depending on the stimulation site and stimulation parameters. However, there is no systematic NIBS review of post-stroke cognitive impairment with a focus on stimulation sites and stimulation parameters. The purpose of this study is to conduct a systematic review and meta-analysis on effectiveness and safety of NIBS for cognitive impairment after a stroke to obtain new insights. This study was prospectively registered with the PROSPERO database of systematic reviews (CRD42020183298). Methods: All English articles from MEDLINE, Scopus, CINAHL, Embase, PsycINFO, and CENTRAL were searched from inception up to 31 December 2020. Randomized and prospective controlled trials were included for the analysis. Studies with at least five individuals post-stroke, whereby at least five sessions of NIBS were provided and using standardized neuropsychological measurement of cognition, were included. We assessed the methodological quality of selected studies as described in the Physiotherapy Evidence Database (PEDro) scoring system. Results: A total of 10 studies met eligibility criteria. Six studies used repetitive transcranial magnetic stimulation (rTMS) and four studies used transcranial direct current stimulation (tDCS). The pooled sample size was 221 and 196 individuals who received rTMS and tDCS respectively. Eight studies combined general rehabilitation, cognitive training, or additional therapy with NIBS. In rTMS studies, target symptoms included global cognition (n = 4), attention (n = 3), memory (n = 4), working memory (WM) (n = 3), and executive function (n = 2). Five studies selected the left dorsolateral prefrontal cortex (DPLFC) as the stimulation target. One rTMS study selected the right DLPFC as the inhibitory stimulation target. Four of six studies showed significant improvement. In tDCS studies, target symptoms included global cognition (n = 2), attention (n = 4), memory (n = 2) and WM (n = 2). Three studies selected the frontal area as the stimulation target. All studies showed significant improvement. In the meta-analysis, rTMS showed a significant effect on attention, memory, WM and global cognition classified by neuropsychological tests. On the other hand, tDCS had no significant effect. Conclusions: In post-stroke patients with deficits in cognitive function, including attention, memory, and WM, NIBS shows promising positive effects. However, this effect is limited, suggesting that further studies are needed with more precision in stimulation sites and stimulation parameters. Future studies using advanced neurophysiological and neuroimaging tools to allow for a network-based approach to treat cognitive symptoms post-stroke with NIBS are warranted.

Diagnosing and managing post-stroke aphasia

Introduction: Aphasia is a debilitating language disorder and even mild forms of aphasia can negatively affect functional outcomes, mood, quality of life, social participation, and the ability to return to work. Language deficits after post-stroke aphasia are heterogeneous. Areas covered: The first part of this manuscript reviews the traditional syndrome-based classification approach as well as recent advances in aphasia classification that incorporate automatic speech recognition for aphasia classification. The second part of this manuscript reviews the behavioral approaches to aphasia treatment and recent advances such as noninvasive brain stimulation techniques and pharmacotherapy options to augment the effectiveness of behavioral therapy. Expert opinion: Aphasia diagnosis has largely evolved beyond the traditional approach of classifying patients into specific syndromes and instead focuses on individualized patient profiles. In the future, there is a great need for more large scale randomized, double-blind, placebo-controlled clinical trials of behavioral treatments, noninvasive brain stimulation, and medications to boost aphasia recovery.

The management of subacute and chronic vascular aphasia: an updated review

Background

Post-stroke aphasia (PSA) is an impairment of the generation or comprehension of language due to acute cerebrovascular lesions. Subacute phase span the 7th day to 24 weeks post-onset while > 6 months is termed chronic phase. Language recovery does not arise immediately in chronic PSA, unlike the acute phase. The majority of the treatment modalities in these two PSA phases are still in the infancy stage, facing dilemmas and considered experimental requiring constant updates. Hence, we aimed to upgrade the existing literature regarding available PSA management options, advances, and drawbacks pertaining to subacute and chronic phases.

Main text

In this review, we analyzed the management options for subacute and chronic vascular aphasia. MEDLINE, through PubMed, ScienceDirect, and Google Scholar were explored for English studies by utilizing the terms “stroke aphasia” Plus “vascular aphasia”; 160,753 articles were retrieved. The latest studies, published from 2016 to July 2020, were selected. Article headings and abstracts were analyzed for relevance and filtered; eventually, 92 articles were included in this review. Various management options were extracted as follows: noninvasive brain stimulation (NIBS), technology-based therapies, speech-language therapy (SLT), pharmacotherapy, music-based therapies, and psychosocial interventions.

Conclusion

The PSA therapy evolves towards more intense SLT therapy, yet the optimal dosage of the emerging high-intensity therapies is controversial. As spinal and cerebellar NIBS, Telespeech, and E-mental health mark PSA's future, distinct pharmacological options remain a dilemma. Across the continuum of care, PSA–depression comorbidity and inadequate PSA post-discharge education to patient’s families are the significant therapeutic challenges. Future therapeutic mechanisms, optimal dose/timing, and tolerability/safety exploration are obliged.

Developments in treating the nonmotor symptoms of stroke

INTRODUCTION

Stroke is among the most common causes of disability worldwide. Nonmotor symptoms of stroke are common and disabling. Many are treatable, and intervention improves the quality of life for stroke survivors.

AREAS COVERED

Here the author summarizes the evidence-based treatment of depression and other mood disorders, aphasia, hemispatial neglect, impairments of emotional communication and empathy, deficits in memory and other cognitive functions, sleep disorders, pain, fatigue, and seizures resulting from stroke. The author focuses on treatments supported by randomized controlled trials (RCTs), from the literature cited in Google Scholar, Embase, and Pubmed.

EXPERT OPINION

While behavioral rehabilitation is the most common intervention for many of the sequelae of stroke, relatively small RCTs support the use of noninvasive brain stimulation (transcranial direct current stimulation and transcranial direct current stimulation) and medications that facilitate neural plasticity and recovery. These noninvasive brain stimulation methods remain investigational for post-stroke symptoms. The strongest evidence for pharmacological intervention is in the domains of post-stroke mood disorders and epilepsy, but additional RCTs are needed to confirm the efficacy of selective serotonin reuptake inhibitors and other medications for improving recovery of cognition, language, and energy after stroke.