Post-stroke Aphasia Research Articles

Adapting a group-based, multimodal aphasia treatment for telehealth – co-design of M-MAT Tele

Multi-Modality Aphasia Treatment (M-MAT) is an effective group intervention for post-stroke aphasia. M-MAT employs interactive card games and the modalities of gesture, drawing, reading, and writing to improve spoken language. However, there are challenges to implementation of group interventions such as M-MAT, particularly for those who cannot travel or live in rural areas. To maximise access to this effective treatment, we aimed to adapt M-MAT to telehealth format (M-MAT Tele). The Human-Centred Design Framework was utilized to guide the adaptation approach. We identified the intended context of use (outpatient/community rehabilitation) and the stakeholders (clinicians, people with aphasia, health service funders). People with aphasia and practising speech pathologists were invited to co-design M-MAT Tele in a series of iterative workshops, to ensure the end product was user-friendly and clinically feasible. The use of co-design allowed us to understand the hardware, software and other constraints and preferences of end users. In particular, clinicians (n = 3) required software compatible with a range of telehealth platforms and people with aphasia (n = 3) valued solutions with minimal technical demands and costs for participants. Co-design within the Human-Centred Design Framework led to a telehealth solution compatible with all major telehealth platforms, with minimal hardware or software requirements. Pilot testing is underway to confirm acceptability of M-MAT Tele to clinicians and people with aphasia, aiming to provide an effective, accessible tool for aphasia therapy in telehealth settings.

Neuromodulation of the Right Motor Cortex of the Lips With Repetitive Transcranial Magnetic Stimulation to Reduce Phonological Impairment and Improve Naming in Three Persons With Aphasia: A Single-Case Experimental Design.

Repetitive transcranial magnetic stimulation (rTMS) can enhance aphasia recovery. Most studies have used inhibitory stimulation targeting the right inferior frontal gyrus. However, the motor cortex, observed to contribute to the prediction of aphasia recovery, is involved in word production and could be an appropriate target for rTMS. We aimed to observe behavioral changes in a picture naming task induced by inhibitory rTMS targeting the right motor cortex of the lips in people with poststroke aphasia. Using a single-case experimental design, we included three participants with chronic poststroke aphasia who had phonological deficits. Each participant performed a verbal picture naming task 3 times a week for 2, 3, or 4 weeks (pseudorandom across participants) to establish a baseline naming ability for each participant. These were not therapy sessions, and no feedback was provided. Then, each participant received the intervention, inhibitory continuous theta burst stimulation targeting the right motor cortex of the lips, 3 times a week for 2 weeks. Naming testing continued 3 times a week, for these latter 2 weeks. No therapy was performed at any time during the study. Visual analysis of the graphs showed a positive effect of rTMS for P2 and P3 on picture naming accuracy and a tendency toward improvement for P1. Statistical analysis showed an improvement after rTMS for P1 (τ = 0.544, p = .013, SETau = 0.288) and P2 (τ = 0.708, p = .001, SETau = 0.235). For P3, even if the intervention allowed some improvement, this was statistically nonsignificant due to a learning effect during the baseline naming testing, which lasted the longest, 4 weeks. Regarding specific language features, phonological errors significantly decreased in all patients. The motor cortex of the lips could be an appropriate target for rTMS to improve naming in people with poststroke aphasia suffering from a phonological deficit. This suggests the possibility to individualize the target for rTMS, according to the patient's linguistic impairment.

Self-Reported Home Program Adherence by People With Aphasia: Exploring Construct Validity.

The study purpose was to compare the practice patterns captured by self-reported logbook data and those recorded by a computerized home program application. The current study is part of a larger single-case research design study aimed at investigating the effect of logbook use on home program adherence in people with aphasia poststroke. Data from six adults with chronic aphasia with interest in improving their reading were used in this secondary analysis. Participants completed reading comprehension therapy tasks using a mobile application and tablet. The activities were self-directed and designed for people with aphasia to complete independently. We created an aphasia-friendly logbook based on best practices to allow participants to record their estimated total minutes practiced. Participants received instructions to practice the reading therapy application 80 min a day 7 days a week for the duration of the study. We calculated the difference in the total time per day recorded by each participant to the application data collected. All participants used the logbook to record their practice. There was a strong relationship between self-reported logbook practice and application-recorded practice for four of the six participants. Individual differences were noted and explored. These results suggest that some people with aphasia can use logbooks with aphasia-friendly modifications to accurately estimate the amount of practice completed outside of therapy sessions.

Repetitive Transcranial Magnetic Stimulation for Action Naming in Aphasia Rehabilitation: A Systematic Review and Meta-Analysis.

Anomia, characterized by difficulty in word retrieval, particularly action verbs, poses a significant challenge in post-stroke aphasia. Repetitive transcranial magnetic stimulation (rTMS) has gained attention for language processing investigations and interventions. This systematic review explores the potential of rTMS as a modality to address action-verb deficits in post-stroke aphasia. We searched MEDLINE via PubMed, CINAHL via Ebsco and Web of Science in February 2024 for English articles (1996-2024). Eligible studies involved post-stroke aphasia action naming rehabilitation with rTMS. In some of these studies, rTMS was combined with speech-language therapy. In total, 10 studies were included in this systematic review. These articles highlight the potential of rTMS in improving verb retrieval deficits. While significant improvements may not be evident, notable progress both before and after intervention is observed in this review. However, it also underscores the need for further research to enhance language recovery for individuals with post-stroke aphasia.

Four dimensions of naturalistic language production in aphasia after stroke.

There is a rich tradition of research on the neuroanatomical correlates of spoken language production in aphasia using constrained tasks (e.g., picture naming), which offer controlled insights into the distinct processes that govern speech and language (i.e., lexical-semantic access, morphosyntactic construction, phonological encoding, speech motor programming/execution). Yet these tasks do not necessarily reflect everyday language use. In contrast, naturalistic language production (also referred to as connected speech or discourse) more closely approximates typical processing demands, requiring the dynamic integration of all aspects of speech and language. The brain bases of naturalistic language production remain relatively unknown, however, in part because of the difficulty in deriving features that are salient, quantifiable, and interpretable relative to both speech-language processes and the extant literature. The present cross-sectional observational study seeks to address these challenges by leveraging a validated and comprehensive auditory-perceptual measurement system that yields four explanatory dimensions of performance-Paraphasia (misselection of words and sounds), Logopenia (paucity of words), Agrammatism (grammatical omissions), and Motor speech (impaired speech motor programming/execution). We used this system to characterize naturalistic language production in a large and representative sample of individuals with acute post-stroke aphasia (n = 118). Scores on each of the four dimensions were correlated with lesion metrics, and multivariate associations among the dimensions and brain regions were then explored. Our findings revealed distinct yet overlapping neuroanatomical correlates throughout the left-hemisphere language network. Paraphasia and Logopenia were associated primarily with posterior regions, spanning both dorsal and ventral streams, which are critical for lexical-semantic access and phonological encoding. In contrast, Agrammatism and Motor speech were associated primarily with anterior regions of the dorsal stream that are involved in morphosyntactic construction and speech motor planning/execution respectively. Collectively, we view these results as constituting a brain-behavior model of naturalistic language production in aphasia, aligning with both historical and contemporary accounts of the neurobiology of spoken language production.

Big data and artificial intelligence in post-stroke aphasia: A mapping review

BACKGROUND: Aphasia is an impairment of language as a result of brain damage which can affect individuals after a stroke. Recent research in aphasia has highlighted new technologies and techniques that fall under the umbrella of big data and artificial intelligence (AI). OBJECTIVES: This review aims to examine the extent, range and nature of available research on big data and AI relating to aphasia post stroke. METHODS: A mapping review is the most appropriate format for reviewing the evidence on a broad and emerging topic such as big data and AI in post-stroke aphasia. Following a systematic search of online databases and a two-stage screening process, data was extracted from the included studies. This analysis process included grouping the research into inductively created categories as the different areas within the research topic became apparent. RESULTS: Seventy-two studies were included in the review. The results showed an emergent body of research made up of meta-analyses and quasi-experimental studies falling into defined categories within big data and AI in post-stroke aphasia. The two largest categories were automation, including automated assessment and diagnosis as well as automatic speech recognition, and prediction and association, largely through symptom-lesion mapping and meta-analysis. CONCLUSIONS: The framework of categories within the research field of big data and AI in post-stroke aphasia suggest this broad topic has the potential to make an increasing contribution to aphasia research. Further research is needed to evaluate the specific areas within big data and AI in aphasia in terms of efficacy and accuracy within defined categories.

Epidemiological, Clinical and Radiological Profiles of Post-stroke Aphasia in Neurology in Abidjan from April to September 2022

Background and purpose: Aphasia is a language disorder that frequently occurs after a cerebrovascular accident. This prospective descriptive study aimed to describe the epidemiological, clinical and radiological profiles of post-stroke aphasia. Materials and method: Patients presenting aphasia after a stroke documented by brain imaging, hospitalized from April to September 2022 in the neurology departments of the Cocody and Treichville University Hospitals were included. Aphasia was screened using the Language Screening Test (LAST). Epidemiological, clinical and radiological data were collected through clinical observation. Results: Of the 217 stroke patients admitted to neurology during the period, 32 presented aphasia (14.7%). The average age was 56 years, with a male predominance (M/F sex ratio of 2.2). The majority of patients had primary or no schooling (87.5%). Arterial hypertension was the most frequent cardiovascular risk factor (50%) and hemiplegia, the most common physical sign (93.8%). The average LAST score for aphasic patients was 5.3 out of 15. We observed that naming and repetition were the most affected components of speaking, with scores below normal in 87.5%. and 88% of cases. Regarding oral comprehension, order execution was the component most affected for 75.1% of patients. In the acute phase of stroke, 50% of cases of aphasia were severe. Radiologically, 75% of patients presented an ischemic stroke with the predilection of the middle cerebral artery. Conclusion: this study highlights the importance of early detection of aphasia in post-stroke patients and rapid treatment to optimize their linguistic recovery.

The effect of mobile application-based technology on post-stroke aphasia: a systematic review.

Enhancing speech-language therapy remains the most effective strategy for improving post-stroke aphasia, However, conventional face-to-face interventions often lack the necessary therapeutic intensity. In recent years, mobile application-based speech-language therapy has emerged progressively, offering new opportunities for independent rehabilitation among aphasic patients. This review aims to evaluate the impact of mobile application-based interventions on post-stroke aphasic. By conducting a systematic search across five databases (PubMed, Web of Science, EMBASE, CINAHL, and Scopus), we identified and included studies that investigated the utilization of mobile application-based technologies (such as computers, iPads, etc.) for treating post-stroke aphasia. This study included 15 research investigations, including 10 randomized controlled trials (RCTs), four self-controlled studies and one cross-over experimental design study. Among these, eight studies demonstrated the efficacy of mobile application-based therapy in enhancing overall language functionality for post-stroke aphasia patients, three studies highlighted its potential for improving communication skills, three studies observed its positive impact on spontaneous speech expression. Moreover, four studies indicated its effectiveness in enhancing naming abilities, two studies underscored the positive influence of mobile application-based interventions on the quality of life for individuals with aphasia. Six studies noted that speech improvement effects were maintained during the follow-up period. The results of this review demonstrate the potential of mobile application-based interventions for improving speech-language function in individuals with aphasia. However, further high-quality research is needed to establish their effects across different domains and to delve into the comparative advantages of various treatment approaches. https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=405248.

Distinct brain morphometry patterns revealed by deep learning improve prediction of post-stroke aphasia severity

BackgroundEmerging evidence suggests that post-stroke aphasia severity depends on the integrity of the brain beyond the lesion. While measures of lesion anatomy and brain integrity combine synergistically to explain aphasic symptoms, substantial interindividual variability remains unaccounted. One explanatory factor may be the spatial distribution of morphometry beyond the lesion (e.g., atrophy), including not just specific brain areas, but distinct three-dimensional patterns.MethodsHere, we test whether deep learning with Convolutional Neural Networks (CNNs) on whole brain morphometry (i.e., segmented tissue volumes) and lesion anatomy better predicts chronic stroke individuals with severe aphasia (N = 231) than classical machine learning (Support Vector Machines; SVMs), evaluating whether encoding spatial dependencies identifies uniquely predictive patterns.ResultsCNNs achieve higher balanced accuracy and F1 scores, even when SVMs are nonlinear or integrate linear or nonlinear dimensionality reduction. Parity only occurs when SVMs access features learned by CNNs. Saliency maps demonstrate that CNNs leverage distributed morphometry patterns, whereas SVMs focus on the area around the lesion. Ensemble clustering of CNN saliencies reveals distinct morphometry patterns unrelated to lesion size, consistent across individuals, and which implicate unique networks associated with different cognitive processes as measured by the wider neuroimaging literature. Individualized predictions depend on both ipsilateral and contralateral features outside the lesion.ConclusionsThree-dimensional network distributions of morphometry are directly associated with aphasia severity, underscoring the potential for CNNs to improve outcome prognostication from neuroimaging data, and highlighting the prospective benefits of interrogating spatial dependence at different scales in multivariate feature space.

The kitchen assessment: an interactional analysis of assessment and feedback between an occupational therapist and a patient with aphasia post stroke

Purpose After stroke, patients undergo frequent multidisciplinary assessments. Little is known about patients’ experiences of being assessed and the impact of assessment interactions and feedback for ongoing engagement in rehabilitation. This research aims to stimulate reflection on clinical interactions, even during routine clinical assessments, and the provision of assessment feedback. Materials and methods This study involved a detailed analysis of an authentic kitchen assessment interaction between an occupational therapist and a patient with aphasia following stroke. It used a speech function analysis based on systemic functional linguistics resulting in both dynamic and synoptic data, and a consideration of interactive framing, to explore assessment explanation and feedback. Results The analysis revealed the clinician’s interactive dominance in terms of number and type of moves, and misalignment of interactional framing at different points in the exchange. The session appeared to result in patient disengagement related both to the clinician’s misjudged response to the patient’s aphasia, and the context of assessment itself, characterised by reliance on question-and-answer exchanges, and a tendency to highlight deficit. Conclusions Assessment sessions may be emotionally challenging for patients after stroke and feedback may be interpreted as bad news. Sensitive communication is required to support psychological wellbeing and engagement in rehabilitation. IMPLICATIONS FOR REHABILITATION After stroke, patients are assessed by the multidisciplinary team to inform intervention and discharge planning. Little is known about the feedback patients receive or their views of this feedback, including when it is perceived as bad news. The presence of aphasia can complicate how assessments are conducted and how feedback is delivered and received. Greater awareness is needed of how feedback following assessment might impact patients’ psychological wellbeing and engagement in rehabilitation.

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

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

High-Intensity Aphasia Intervention Is Minimally Fatiguing in Chronic Aphasia: An Analysis of Participant Self-Ratings From a Large Randomized Controlled Trial.

High-intensity therapy is recommended in current treatment guidelines for chronic poststroke aphasia. Yet, little is known about fatigue levels induced by treatment, which could interfere with rehabilitation outcomes. We analyzed fatigue experienced by people with chronic aphasia (>6 months) during high-dose interventions at 2 intensities. A retrospective observational analysis was conducted on self-rated fatigue levels of people with chronic aphasia (N=173) collected during a previously published large randomized controlled trial of 2 treatments: constraint-induced aphasia therapy plus and multi-modality aphasia therapy. Interventions were administered at a higher intensity (30 hours over 2 weeks) or lower intensity (30 hours over 5 weeks). Participants rated their fatigue on an 11-point scale before and after each day of therapy. Data were analyzed using Bayesian ordinal multilevel models. Specifically, we considered changes in self-rated participant fatigue across a therapy day and over the intervention period. Data from 144 participants was analyzed. Participants were English speakers from Australia or New Zealand (mean age, 62 [range, 18-88] years) with 102 men and 42 women. Most had mild (n=115) or moderate (n=52) poststroke aphasia. Median ratings of the level of fatigue by people with aphasia were low (1 on a 0-10-point scale) at the beginning of the day. Ratings increased slightly (+1.0) each day after intervention, with marginally lower increases in the lower intensity schedule. There was no evidence of accumulating fatigue over the 2- or 5-week interventions. Findings suggest that intensive intervention was not associated with large increases in fatigue for people with chronic aphasia enrolled in the COMPARE trial (Constraint-Induced or Multimodality Personalised Aphasia Rehabilitation). Fatigue did not change across the course of the intervention. This study provides evidence that intensive treatment was minimally fatiguing for stroke survivors with chronic aphasia, suggesting that fatigue is not a barrier to high-intensity treatment.

An evaluation of the validity of an aphasia friendly mood and anxiety measure for stroke patients

ABSTRACT Introduction People with post-stroke aphasia are at increased risk of experiencing depression and anxiety. Despite this, there is a lack of appropriate tools which can be used in routine stroke rehabilitation practice to support with the identification of patients experiencing these difficulties. The Stroke Aphasia Anxiety and Mood Screen (SAAMS) was developed by an interdisciplinary team of stroke rehabilitation professionals to improve mood and anxiety screening. The current study sought to evaluate the validity of this measure. Methods Twenty-one people undergoing in-patient stroke rehabilitation who experienced aphasia were administered the SAAMS, alongside the Stroke Aphasic Depression Questionnaire (SADQ-H10) and the Behavioural Outcomes of Anxiety (BOA). The inclusion criteria included patients whose aphasia prevented them from completing traditional self-report measures of mood and anxiety, but who demonstrated a reliable ability to correctly respond to yes/no closed questions in Speech and Language Therapy assessments. Results Both the SAAMS-anxiety (SAAMS-A) and depression (SAAMS-D) subscales achieved adequate internal consistency, and patients’ scores were correlated with observational measures of mood and anxiety. The SAAMS achieved fair classification accuracy for identifying clinical depression and anxiety. Conclusions Patients with aphasia provided reliable responses to questions about anxiety and depression, and this is of clinical importance. While the study identified that the SAAMS has reasonable classification accuracy, further research is required to validate the SAAMS more thoroughly before it can be used routinely in clinical practice.

Lesion-symptom Mapping of Acceptability Judgments in Chronic Poststroke Aphasia Reveals the Neurobiological Underpinnings of Receptive Syntax.

Disagreements persist regarding the neural basis of syntactic processing, which has been linked both to inferior frontal and posterior temporal regions of the brain. One focal point of the debate concerns the role of inferior frontal areas in receptive syntactic ability, which is mostly assessed using sentence comprehension involving complex syntactic structures, a task that is potentially confounded with working memory. Syntactic acceptability judgments may provide a better measure of receptive syntax by reducing the need to use high working memory load and complex sentences and by enabling assessment of various types of syntactic violations. We therefore tested the perception of grammatical violations by people with poststroke aphasia (n = 25), along with matched controls (n = 16), using English sentences involving errors in word order, agreement, or subcategorization. Lesion data were also collected. Control participants performed near ceiling in accuracy with higher discriminability of agreement and subcategorization violations than word order; aphasia participants were less able to discriminate violations, but, on average, paralleled control participants discriminability of types of violations. Lesion-symptom mapping showed a correlation between discriminability and posterior temporal regions, but not inferior frontal regions. We argue that these results diverge from models holding that frontal areas are amodal core regions in syntactic structure building and favor models that posit a core hierarchical system in posterior temporal regions.

The impact of aphasia on the marital relationship from the perspective of people with post-stroke aphasia and their partners: a case-control study

ABSTRACT Introduction Aphasia is the result of neurological damage that leads to disorders in the individual’s expressive and/or receptive language. Communication difficulties adversely impact various aspects of the person’s life, and relationships are no exception. Marital relationships might be influenced by health conditions, and possibly by aphasia. Objectives This study aimed to compare marital adjustment between couples in which one of the people suffered a stroke and had aphasia with couples in which the person who had a stroke did not have aphasia. Methods and Procedures This is a cross-sectional case-control, quantitative and qualitative study, which included people affected by stroke and their spouses, in which one of the people in the dyad had post-stroke aphasia of expression (study group) or stroke without aphasia (control group). Data collection was carried out by applying the study’s own questionnaire and the Revised and Validated Dyadic Adjustment Scale, Portuguese version, (RDAS-P) in person or by phone. Results 35 participants were included, who were divided into a study group (n = 11) and a control group (n = 11); their marital partners were classified into partners of the study group (n = 7) and partners of the control group (n = 6). No statistically significant difference was observed between the groups regarding sociodemographic and clinical data, nor regarding the outcomes of interest. Different correlations were found into the groups. Qualitative results showed differences in the perception of changes in relationships in each group. Conclusions There was no difference in measures of marital adjustment between individuals who had a stroke with and without aphasia. However, the varying correlations and reports found suggest that the groups experience marital issues differently.

GRN knockdown regulates the expression and alternative splicing of genes associated with aphasia-related diseases in PC12 cells

BackgroundPrior research has shown that granulin precursor (GRN, also termed PGRN) is closely linked to aphasia. However, there has been little research on the mechanism of action of GRN in post-stroke aphasia (PSA). MethodsIn this study, RT-qPCR was used to identify variations in gene expression, while RNA sequencing (RNA-seq) was utilized to acquire transcriptional profiles. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were employed for bioinformatics analysis. ResultsGRN was considerably more active in PSA subjects. After silencing the GRN, 197 transcripts had differential expression, and 237 alternative splicing events (ASEs) were substantially affected. The analysis of differentially expressed genes (DEGs) using GO and KEGG approaches showed that these genes have various molecular functions and are significantly enriched in metabolic signaling pathways. Regarding Alternative Splicing (AS), the GO and KEGG analyses revealed numerous functional genes involved in transcription and metabolism. ConclusionsThe knockdown of GRN has been shown to be associated with alterations in transcription, metabolism, and ASEs, potentially impacting transcriptional and metabolic pathways through its involvement in AS. Furthermore, GRN knockdown is associated with nervous system disease-related gene transcription and AS processes, as well as its involvement in G protein-coupled receptor (GPCR) and wingless/integrated (Wnt) signaling pathways, which impact the initiation and resolution of PSA.

Clinical characteristics of post-stroke basal ganglia aphasia and the study of language-related white matter tracts based on diffusion spectrum imaging

BackgroundStroke often damages the basal ganglia, leading to atypical and transient aphasia, indicating that post-stroke basal ganglia aphasia (PSBGA) may be related to different anatomical structural damage and functional remodeling rehabilitation mechanisms. The basal ganglia contain dense white matter tracts (WMTs). Hence, damage to the functional tract may be an essential anatomical structural basis for the development of PSBGA. MethodsWe first analyzed the clinical characteristics of PSBGA in 28 patients and 15 healthy controls (HCs) using the Western Aphasia Battery and neuropsychological test batteries. Moreover, we investigated white matter injury during the acute stage using diffusion magnetic resonance imaging scans for differential tractography. Finally, we used multiple regression models in correlation tractography to analyze the relationship between various language functions and quantitative anisotropy (QA) of WMTs. ResultsCompared with HCs, patients with PSBGA showed lower scores for fluency, comprehension (auditory word recognition and sequential commands), naming (object naming and word fluency), reading comprehension of sentences, Mini-Mental State Examination, and Montreal Cognitive Assessment, along with increased scores in Hamilton Anxiety Scale-17 and Hamilton Depression Scale-17 within 7 days after stroke onset (P < 0.05). Differential tractography revealed that patients with PSBGA had damaged fibers, including in the body fibers of the corpus callosum, left cingulum bundles, left parietal aslant tracts, bilateral superior longitudinal fasciculus II, bilateral thalamic radiation tracts, left fornix, corpus callosum tapetum, and forceps major, compared with HCs (FDR < 0.02). Correlation tractography highlighted that better comprehension was correlated with a higher QA of the left inferior fronto-occipital fasciculus (IFOF), corpus callosum forceps minor, and left extreme capsule (FDR < 0.0083). Naming was positively associated with the QA of the left IFOF, forceps minor, left arcuate fasciculus, and uncinate fasciculus (UF) (FDR < 0.0083). Word fluency of naming was also positively associated with the QA of the forceps minor, left IFOF, and thalamic radiation tracts (FDR < 0.0083). Furthermore, reading was positively correlated with the QA of the forceps minor, left IFOF, and UF (FDR < 0.0083). ConclusionPSBGA is primarily characterized by significantly impaired word fluency of naming and preserved repetition abilities, as well as emotional and cognitive dysfunction. Damaged limbic pathways, dorsally located tracts in the left hemisphere, and left basal ganglia pathways are involved in PSBGA pathogenesis. The results of connectometry analysis further refine the current functional localization model of higher-order neural networks associated with language functions.

Structural network topology associated with naming improvements following intensive aphasia therapy in post-stroke aphasia

A stroke can disrupt the finely tuned language network resulting in aphasia, a language impairment. Though many stroke survivors with aphasia recover within the first 6 months, a significant proportion have lasting deficits. The factors contributing to optimal treatment response remain unclear. Some evidence suggests that increased modularity or fragmentation of brain networks may underlie post-stroke aphasia severity and the extent of recovery. We examined associations between network organization and aphasia recovery in sixteen chronic stroke survivors with non-fluent aphasia following 35 h of Multi-Modality Aphasia Therapy over 10 days and 20 healthy controls who underwent imaging at a single timepoint. Using diffusion-weighted scans obtained before and after treatment, we constructed whole-brain structural connectomes representing the number of probabilistic streamlines between brain regions. Graph theory metrics were quantified for each connectome using the Brain Connectivity Toolbox. Correlations were examined between graph metrics and speech performance measured using the Boston Naming Test (BNT) at pre-, post- and 3-months post-intervention. Compared to controls, participants with stroke demonstrated higher whole-brain modularity at pre-treatment. Modularity did not differ between pre- and post-treatment. In individuals who responded to therapy, higher pre-treatment modularity was associated with worse performance on the BNT. Moreover, higher pre-treatment participation coefficients (i.e., how well a region is connected outside its own module) for the left IFG, planum temporale, and posterior temporal gyri were associated with greater improvements at post-treatment. These results suggest that pre-treatment network topology may impact therapeutic gains, highlighting the influence of network organization on post-stroke aphasia recovery.

Exploring neural tracking of acoustic and linguistic speech representations in individuals with post-stroke aphasia.

Aphasia is a communication disorder that affects processing of language at different levels (e.g., acoustic, phonological, semantic). Recording brain activity via Electroencephalography while people listen to a continuous story allows to analyze brain responses to acoustic and linguistic properties of speech. When the neural activity aligns with these speech properties, it is referred to as neural tracking. Even though measuring neural tracking of speech may present an interesting approach to studying aphasia in an ecologically valid way, it has not yet been investigated in individuals with stroke-induced aphasia. Here, we explored processing of acoustic and linguistic speech representations in individuals with aphasia in the chronic phase after stroke and age-matched healthy controls. We found decreased neural tracking of acoustic speech representations (envelope and envelope onsets) in individuals with aphasia. In addition, word surprisal displayed decreased amplitudes in individuals with aphasia around 195 ms over frontal electrodes, although this effect was not corrected for multiple comparisons. These results show that there is potential to capture language processing impairments in individuals with aphasia by measuring neural tracking of continuous speech. However, more research is needed to validate these results. Nonetheless, this exploratory study shows that neural tracking of naturalistic, continuous speech presents a powerful approach to studying aphasia.

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

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. 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. 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. 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.