Inner speech in the daily lives of people with aphasia.

Introduction: This exploratory, preliminary, feasibility study evaluated the extent to which adults with chronic aphasia (N = 23) report experiencing inner speech in their daily lives by leveraging experience sampling and survey methodology. Methods: The presence of inner speech was assessed at 30 time-points and themes of inner speech at three time-points, over the course of three weeks. The relationship of inner speech to aphasia severity, demographic information (age, sex, years post-stroke), and insight into language impairment was evaluated. Results: There was low attrition (<8%) and high compliance (>94%) for the study procedures, and inner speech was experienced in most sampled instances (>78%). The most common themes of inner speech experience across the weeks were 'when remembering', 'to plan', and 'to motivate oneself'. There was no significant relationship identified between inner speech and aphasia severity, insight into language impairment, or demographic information. In conclusion, adults with aphasia tend to report experiencing inner speech often, with some shared themes (e.g., remembering, planning), and use inner speech to explore themes that are uncommon in young adults in other studies (e.g., to talk to themselves about health). Discussion: High compliance and low attrition suggest design feasibility, and results emphasize the importance of collecting data in age-similar, non-brain-damaged peers as well as in adults with other neurogenic communication disorders to fully understand the experience and use of inner speech in daily life. Clinical implications and future directions are discussed.

A scoping review of transcription-less practices for analysis of aphasic discourse and implications for future research.

BACKGROUND: It is important to capture a comprehensive language profile from speakers with aphasia. One way to do this is to evaluate spoken discourse, which is language beyond a single simple clause used for a specific purpose. While the historical trend in aphasiology has been to capture performance during isolated language tasks, such as confrontation naming, there is a demonstrated need and benefit to collecting language information from tasks that resemble everyday communication. As a result, there has been an increase in discourse analysis research over time. However, despite clinicians' and researchers' desire to analyse spoken discourse, they are faced with critical barriers that inhibit implementation. AIMS: To use scoping review methodology to identify transcription-less tools developed to analyse discourse from individuals with aphasia. The review addressed the following question: 'What transcription-less tools and analysis procedures are available to assess discourse in people with aphasia?' and included several sub-questions to further characterise the type of discourse and tool being used, participants on whom the tool was used to rate discourse abilities, tool users (raters), and psychometric properties. METHODS: The scoping review was conducted between the months of October 2022 and January 2023, concluding 30 January 2023, on PubMed/NCBI, Academic Search Complete and Linguistics and Language Behavior Abstracts. Major inclusion parameters included peer-reviewed papers written in English; that the tool was used to analyse discourse elicited by individuals with acquired aphasia; and that the tool was not a part of a standardised battery or assessment. Perceptual discourse analysis was defined as any analysis which primarily relied on listener impressions and did not numerically quantify specific language behaviours. 'Transcription-less' analysis was defined as any discourse analysis which did not require a written record of the discourse sample in order to be completed. A total of 396 abstracts were screened and 39 full articles were reviewed, yielding 21 papers that were included in the review. MAIN CONTRIBUTION: An overview of the state of transcription-less tools for aphasic discourse analysis is provided, and next steps are identified to facilitate increased implementation of discourse analysis in clinical and research settings. CONCLUSION: Transcription-less tools have many benefits for analysing multiple levels (e.g., linguistic, propositional, macrostructural, pragmatic) of discourse, but require more research to establish sound psychometric properties and to explore the implementation of these tools in clinical settings. WHAT THIS PAPER ADDS: What is already known on this subject Individuals with aphasia prioritise treatment outcomes at the discourse level such as being able to engage in conversations with friends and family about important topics and participating in social and leisure activities. However, discourse is rarely used as a treatment outcome measure in clinical practice due to multiple barriers. When speech-language pathologists do assess discourse, they often make perceptual judgements without transcribing the discourse sample. Transcription-less analysis procedures may improve clinical implementation of discourse assessment, which would better match treatment outcome measurement to clients' desired outcomes. However, little is known about the current state of transcription-less discourse analysis, blocking progress. What this paper adds to existing knowledge This study provides an overview of currently available transcription-less discourse analysis procedures that are not part of published standardised aphasia assessments. Transcription-less measures are available to evaluate discourse at all levels (i.e., lexical, propositional, macro-structural/planning, and pragmatic) and most measures include items that assess discourse abilities across multiple levels. Additionally, there are transcription-less measures available for both structured (e.g., picture scene description) and spontaneous (e.g., conversation) discourse tasks. However, current transcription-less procedures are lacking psychometric data including information about validity and reliability. What are the potential or actual clinical implications of this work? Transcription-less analysis methods may provide an avenue for increased implementation of discourse measurement into clinical practice. Further research is needed to determine the clinical utility of transcription-less discourse analysis to better monitor clients' desired treatment outcomes.

The Communication Success Screener: A Preliminary Investigation of Perceived Communicative Success Across Modalities, Environments, and Demands.

PURPOSE: Behavioral intervention targeting speech, language, and communication concerns is an established therapeutic approach for patients with communication concerns across a range of acquired neurogenic disorders. The multidimensional factors that contribute to a person's self-identified communication challenges and strengths in their daily communication needs must be considered to provide functional and person-centered care. While assessments grounded in clinician observation or client self-report exist, there is a direct need for a screening tool that comprehensively evaluates the roles of modality (verbal, text, gesture) and environment (in-person, virtual) on self-reported success across communicative demands. In this study, we describe a preliminary approach to monitoring the progression of receptive and expressive communication skills in people with chronic poststroke aphasia in the context of communication practices of the 21st century, culminating in the development and exploratory implementation of a novel clinical instrument: the Communication Success Screener (COMSS). METHOD: Thirty-three participants with aphasia due to stroke were recruited to complete and evaluate the COMSS via an online survey. Quantitative responses and open-ended participant feedback were collected to validate and propose adaptations to the COMSS. Group-level analyses and case presentations were used to highlight COMSS features and outcomes. RESULTS: Participant responses to the COMSS questionnaire suggest that this screening tool creates differentiated communicative success profiles based on self-report. Participant feedback also indicated that the COMSS appropriately evaluates self-reported success across modalities of verbal, text, and gesture in the context of in-person and virtual environments. CONCLUSIONS: The communication concerns experienced by people with aphasia are often heterogeneous and vary as a function of their daily activities of living, preferred language modalities, and environmental supports. We present preliminary feasibility analyses of the COMSS as a potential tool to support the monitoring of functional change by evaluating self-reported communicative success across form, modality, environment, and task demand. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24521044.

Test-Retest Reliability of Microlinguistic Information Derived From Spoken Discourse in Persons With Chronic Aphasia.

PURPOSE: The purpose of this study was to characterize test-retest reliability of discourse measures across a battery of common tasks in individuals with aphasia and prospectively matched adults without brain damage. METHOD: We collected spoken discourse during five monologue tasks at two timepoints (test and retest; within 2 weeks apart) in an aphasia group (n = 23) and a peer group with no brain damage (n = 24). We evaluated test-retest reliability for percentage of correct information units, correct information units per minute, mean length of utterance, verbs per utterance, noun/verb ratio, open/closed class word ratio, tokens, sample duration (seconds), propositional idea density, type-token ratio, and words per minute. We explored reliability's relationship with sample length and aphasia severity. RESULTS: Rater reliability was excellent. Across tasks, both groups demonstrated discourse measures with poor, moderate, and good reliability, with the aphasia group having measures demonstrating excellent test-retest reliability. When evaluating measures within each task, test-retest reliability again ranged from poor to excellent for both groups. Across groups and task, measures that appeared most reliable appeared to reflect lexical, informativeness, or fluency information. Sample length and aphasia severity impacted reliability, and this differed across and by task. CONCLUSIONS: We identified several discourse measures that were reliable across and within tasks. Test-retest statistics are intimately linked to the specific sample, emphasizing the importance of multiple baseline studies. Task itself should be considered an important variable, and it should not be assumed that discourse measures found to be reliable across several tasks (averaged) are likewise reliable for a single task. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.23298032.

Neural correlates of verbal fluency revealed by longitudinal T1, T2 and FLAIR imaging in stroke.

Diffusion-weighted imaging has been widely used in the research on post-stroke verbal fluency but acquiring diffusion data is not always clinically feasible. Achieving comparable reliability for detecting brain variables associated with verbal fluency impairments, based on more readily available anatomical, non-diffusion images (T1, T2 and FLAIR), enables clinical practitioners to have complementary neurophysiological information at hand to facilitate diagnosis and treatment of language impairment. Meanwhile, although the predominant focus in the stroke recovery literature has been on cortical contributions to verbal fluency, it remains unclear how subcortical regions and white matter disconnection are related to verbal fluency. Our study thus utilized anatomical scans of ischaemic stroke survivors (n = 121) to identify longitudinal relationships between subcortical volume, white matter tract disconnection, and verbal fluency performance at 3- and 12-months post-stroke. Subcortical grey matter volume was derived from FreeSurfer. We used an indirect probabilistic approach to quantify white matter disconnection in terms of disconnection severity, the proportion of lesioned voxel volume to the total volume of a tract, and disconnection probability, the probability of the overlap between the stroke lesion and a tract. These disconnection variables of each subject were identified based on the disconnectome map of the BCBToolkit. Using a linear mixed multiple regression method with 5-fold cross-validations, we correlated the semantic and phonemic fluency scores with longitudinal measurements of subcortical grey matter volume and 22 bilateral white matter tracts, while controlling for demographic variables (age, sex, handedness and education), total brain volume, lesion volume, and cortical thickness. The results showed that the right subcortical grey matter volume was positively correlated with phonemic fluency averaged over 3 months and 12 months. The finding generalized well on the test data. The disconnection probability of left superior longitudinal fasciculus II and left posterior arcuate fasciculus was negatively associated with semantic fluency only on the training data, but the result aligned with our previous study using diffusion scans in the same clinical population. In sum, our results presented evidence that routinely acquired anatomical scans can serve as a reliable source for deriving neural variables of post-stroke verbal fluency performance. The use of this method might provide an ecologically valid and more readily implementable analysis tool.

Validation of an Automated Procedure for Calculating Core Lexicon From Transcripts.

PURPOSE: The aim of this study was to advance the use of structured, monologic discourse analysis by validating an automated scoring procedure for core lexicon (CoreLex) using transcripts. METHOD: Forty-nine transcripts from persons with aphasia and 48 transcripts from persons with no brain injury were retrieved from the AphasiaBank database. Five structured monologic discourse tasks were scored manually by trained scorers and via automation using a newly developed CLAN command based upon previously published lists for CoreLex. Point-to-point (or word-by-word) accuracy and reliability of the two methods were calculated. Scoring discrepancies were examined to identify errors. Time estimates for each method were calculated to determine if automated scoring improved efficiency. RESULTS: Intraclass correlation coefficients for the tasks ranged from .998 to .978, indicating excellent intermethod reliability. Automated scoring using CLAN represented a significant time savings for an experienced CLAN user and for inexperienced CLAN users following step-by-step instructions. CONCLUSIONS: Automated scoring of CoreLex is a valid and reliable alternative to the current gold standard of manually scoring CoreLex from transcribed monologic discourse samples. The downstream time saving of this automated analysis may allow for more efficient and broader utilization of this discourse measure in aphasia research. To further encourage the use of this method, go to https://aphasia.talkbank.org/discourse/CoreLexicon/ for materials and the step-by-step instructions utilized in this project. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.20399304.

Task-Specific Iconic Gesturing During Spoken Discourse in Aphasia.

PURPOSE: In persons living with aphasia, we will explore the relationship between iconic gesture production during spontaneous speech and discourse task, spoken language, and demographic information. METHOD: Employing the AphasiaBank database, we coded iconic gestures in 75 speakers with aphasia during two spoken discourse tasks: a procedural narrative, which involved participants telling the experimenter how to make a sandwich ("Sandwich"), and a picture sequence narrative, which had participants describe the picture sequence to the experimenter ("Window"). Forty-three produced a gesture during both tasks, and we further evaluate data from this subgroup as a more direct comparison between tasks. RESULTS: More iconic gestures, at a higher rate, were produced during the procedural narrative. For both tasks, there was a relationship between iconic gesture rate, modeled as iconic gestures per word, and metrics of language dysfluency extracted from the discourse task as well as a metric of fluency extracted from a standardized battery. Iconic gesture production was correlated with aphasia duration, which was driven by performance during only a single task (Window), but not with other demographic metrics, such as aphasia severity or age. We also provide preliminary evidence for task differences shown through the lens of two types of iconic gestures. CONCLUSIONS: While speech-language pathologists have utilized gesture in therapy for poststroke aphasia, due to its possible facilitatory role in spoken language, there has been considerably less work in understanding how gesture differs across naturalistic tasks and how we can best utilize this information to better assess gesture in aphasia and improve multimodal treatment for aphasia. Furthermore, our results contribute to gesture theory, particularly, about the role of gesture across naturalistic tasks and its relationship with spoken language. Supplemental Material https://doi.org/10.23641/asha.14614941.

Functional differentiation in the language network revealed by lesion-symptom mapping.

Theories of language organization in the brain commonly posit that different regions underlie distinct linguistic mechanisms. However, such theories have been criticized on the grounds that many neuroimaging studies of language processing find similar effects across regions. Moreover, condition by region interaction effects, which provide the strongest evidence of functional differentiation between regions, have rarely been offered in support of these theories. Here we address this by using lesion-symptom mapping in three large, partially-overlapping groups of aphasia patients with left hemisphere brain damage due to stroke (N = 121, N = 92, N = 218). We identified multiple measure by region interaction effects, associating damage to the posterior middle temporal gyrus with syntactic comprehension deficits, damage to posterior inferior frontal gyrus with expressive agrammatism, and damage to inferior angular gyrus with semantic category word fluency deficits. Our results are inconsistent with recent hypotheses that regions of the language network are undifferentiated with respect to high-level linguistic processing.

Suggestions for Improving the Investigation of Gesture in Aphasia.

Purpose When we speak, we gesture, and indeed, persons with aphasia gesture more frequently. The reason(s) for this is still being investigated, spurring an increase in the number of studies of gesture in persons with aphasia. As the number of studies increases, so too does the need for a shared set of best practices for gesture research in aphasia. After briefly reviewing the importance and use of gesture in persons with aphasia, this viewpoint puts forth methodological and design considerations when evaluating gesture in persons with aphasia. Method & Results We explore several different design and methodological considerations for gesture research specific to persons with aphasia, such as video angle specifications, data collection techniques, and analysis considerations. The goal of these suggestions is to develop transparent and reproducible methods for evaluating gesture in aphasia to build a solid foundation for continued work in this area. Conclusions We have proposed that it is critical to evaluate multimodal communication in a methodologically robust way to facilitate increased knowledge about the relationship of gesture to spoken language, cognition, and to other aspects of living with aphasia and recovery from aphasia. We conclude by postulating future directions for gesture research in aphasia.

Spoken Discourse Assessment and Analysis in Aphasia: An International Survey of Current Practices.

Purpose Spoken discourse analysis is commonly employed in the assessment and treatment of people living with aphasia, yet there is no standardization in assessment, analysis, or reporting procedures, thereby precluding comparison/meta-analyses of data and hindering replication of findings. An important first step is to identify current practices in collecting and analyzing spoken discourse in aphasia. Thus, this study surveyed current practices, with the goal of working toward standardizing spoken discourse assessment first in research settings with subsequent implementation into clinical settings. Method A mixed-methods (quantitative and qualitative) survey was publicized to researchers and clinicians around the globe who have collected and/or analyzed spoken discourse data in aphasia. The survey data were collected between September and November 2019. Results Of the 201 individuals who consented to participate, 189 completed all mandatory questions in the survey (with fewer completing nonmandatory response questions). The majority of respondents reported barriers to utilizing discourse including transcription, coding, and analysis. The most common barrier was time (e.g., lack of time). Respondents also indicated that there was a lack of, and a need for, psychometric properties and normative data for spoken discourse use in the assessment and treatment of persons with aphasia. Quantitative and qualitative results are described in detail. Conclusions The current survey study evaluated spoken discourse methods in aphasia across research and clinical settings. Findings from this study will be used to guide development of process standardization in spoken discourse and for the creation of a psychometric and normative property database. Supplemental Material https://doi.org/10.23641/asha.166395100.

Conducting a Virtual Study With Special Considerations for Working With Persons With Aphasia.

Purpose The use of technology (e.g., telehealth) in clinical settings has rapidly increased, and its use in research settings continues to grow. The aim of this report is to present one potential solution to a clinical issue that of virtual and remote assessment for the purposes of spoken language research in persons with aphasia (PWA). To do so, we report detailed methods for conducting a multitimepoint (test-retest) virtual paradigm, assessing lifestyle, physiological, cognitive, and linguistic factors in persons with and without aphasia. Method Procedures for virtual assessment are detailed in a sample of adults with no brain damage (N = 24) and PWA (N = 25) on a test-retest paradigm (data collection approximately 10 ± 3 days apart). This report provides practical information about pre-assessment (e.g., recruitment, scheduling), assessment (e.g., aphasia-friendly consent presentation, investigator fidelity), and postassessment (e.g., data storage, quality check) procedures for human behavior research using a virtual platform. Results Preliminary study data are provided, indicating high retention rates, high rates of data acquisition, and feasibility. Common technological troubles and solutions are discussed, and solutions are offered. The results suggest that our pre-assessment, assessment, and postassessment procedures contributed to the success of our study. Conclusions We provide a practical methodology for conducting a multitimepoint study, with considerations for PWA, adding to the body of research on telehealth in clinical populations. Future studies should continue to evaluate telemethodology, which may be core for diversifying studies, improving study retention, and enrolling larger sample sizes. Supplemental Material https://doi.org/10.23641/asha.14608101.

Effect of Stroke on Contralateral Functional Connectivity.

Introduction: Stroke can induce large-scale functional reorganization of the brain; however, the spatial patterns of this reorganization remain largely unknown. Methods: Using a large (N = 116) sample of participants who were in the chronic stages of stroke, we present a systematic study of the association between brain damage and functional connectivity (FC) within the intact hemisphere. We computed correlations between regional cortical damage and contralateral FC. Results: We identified left-hemisphere regions that had the most pronounced effect on the right-hemisphere FC, and, conversely, right-hemisphere connections where the effect of damage was particularly strong. Notably, the vast majority of significant correlations were positive: damage was associated with an increase in regional contralateral connectivity. Discussion: These findings lend evidence of the reorganization of contralateral cortical networks as a response to brain damage, which is more pronounced in a set of well-connected regions where connectivity increases with the amount of damage. Impact statement The relatively large sample size combined with our best-of-breed analysis methods provides us with sufficient statistical power and spatial sensitivity to identify a set of brain regions where damage has the strongest impact on contralateral networks, and a set of contralateral functional connections that increase in strength in response to brain damage. Our results demonstrate that the brain's ability to reorganize itself after extensive damage is not distributed equally in space, but is more likely to occur in specific core regions. We believe that the associations between brain damage and increased connectivity in the "intact" hemisphere provide novel, and important, insight into the plasticity of the adult brain.

Standardizing Assessment of Spoken Discourse in Aphasia: A Working Group With Deliverables.

Purpose The heterogeneous nature of measures, methods, and analyses reported in the aphasia spoken discourse literature precludes comparison of outcomes across studies (e.g., meta-analyses) and inhibits replication. Furthermore, funding and time constraints significantly hinder collecting test-retest data on spoken discourse outcomes. This research note describes the development and structure of a working group, designed to address major gaps in the spoken discourse aphasia literature, including a lack of standardization in methodology, analysis, and reporting, as well as nominal data regarding the psychometric properties of spoken discourse outcomes. Method The initial initiatives for this working group are to (a) propose recommendations regarding standardization of spoken discourse collection, analysis, and reporting in aphasia, based on the results of an international survey and a systematic literature review and (b) create a database of test-retest spoken discourse data from individuals with and without aphasia. The survey of spoken discourse collection, analysis, and interpretation procedures was distributed to clinicians and researchers involved in aphasia assessment and rehabilitation from September to November 2019. We will publish survey results and recommend standards for collecting, analyzing, and reporting spoken discourse in aphasia. A multisite endeavor to collect test-retest spoken discourse data from individuals with and without aphasia will be initiated. This test-retest information will be contributed to a central site for transcription and analysis, and data will be subsequently openly curated. Conclusion The goal of the working group is to create recommendations for field-wide standards in methods, analysis, and reporting of spoken discourse outcomes, as has been done across other related disciplines (e.g., Consolidated Standards of Reporting Trials, Enhancing the Quality and Transparency of Health Research, Committee on Best Practice in Data Analysis and Sharing). Additionally, the creation of a database through our multisite collaboration will allow the identification of psychometrically sound outcome measures and norms that can be used by clinicians and researchers to assess spoken discourse abilities in aphasia.

Developing, Implementing, and Improving Assessment and Treatment Fidelity in Clinical Aphasia Research.

Purpose The purpose of this study was to describe the development and implementation of a fidelity program for an ongoing, multifacility, aphasia intervention study and to explain how initial fidelity measures are being used to improve study integrity. Method A Clinical Core team developed and incorporated a fidelity plan in this study. The aims of the Clinical Core team were to (a) supervise data collection and data management at each clinical site, (b) optimize and monitor assessment fidelity, and (c) optimize and monitor treatment fidelity. Preliminary data are being used to guide ongoing efforts to preserve and improve the fidelity of this intervention study. Results Preliminary results show that specific recruitment strategies help to improve appropriate referrals and that accommodations to participants and their families help to maintain excellent retention. A streamlined and centralized training program assures the reliability of assessors and raters for the study's assessment and treatment protocols. Ongoing monitoring of both assessment and treatment tasks helps to maintain study integrity. Less-than-optimal interrater reliability data for the raters of some of the discourse measures guided the Clinical Core team to address the training and coding inconsistencies in a timely manner. Conclusions The creation of a Clinical Core team is instrumental in developing and implementing a fidelity plan for improved assessment and treatment fidelity. Intentional planning and assignment of study staff to implement and monitor ongoing fidelity measures assures that clinical data are reliable and valid. Ongoing review of the plan shows areas of strengths and weaknesses for continuing adjustments and improvement of study fidelity.

Agrammatism and Paragrammatism: A Cortical Double Dissociation Revealed by Lesion-Symptom Mapping.

The fundamental distinction of grammatical deficits in aphasia, agrammatism and paragrammatism, was made over a century ago. However, the extent to which the agrammatism/paragrammatism distinction exists independently of differences in speech fluency has not clearly been investigated. Despite much research on agrammatism, the lesion correlates of paragrammatism are essentially unknown. Lesion-symptom mapping was used to investigate the degree to which the lesion correlates of agrammatism and paragrammatism overlap or dissociate. Four expert raters assessed videos of 53 right-handed patients with aphasia following chronic left-hemisphere stroke retelling the Cinderella story. Consensus discussion determined each subject's classification with respect to grammatical deficits as Agrammatic, Paragrammatic, Both, or No Grammatical Deficit. Each subject's lesion was manually drawn on a high-resolution MRI and warped to standard space for group analyses. Lesion-symptom mapping analyses were performed in NiiStat including lesion volume as a covariate. Secondary analyses included speech rate (words per minute) as an additional covariate. Region of interest analyses identified a double dissociation between these syndromes: damage to Broca's area was significantly associated with agrammatism, p = 0.001 (but not paragrammatism, p = 0.930), while damage to the left posterior superior and middle temporal gyri was significantly associated with paragrammatism, p < 0.001 (but not agrammatism, p = 0.873). The same results obtained when regressing out the effect of speech rate, and nonoverlapping lesion distributions between the syndromes were confirmed by uncorrected whole brain analyses. Our results support a fundamental distinction between agrammatism and paragrammatism.

Brain Damage Associated with Impaired Sentence Processing in Acute Aphasia.

Left-hemisphere brain damage commonly affects patients' abilities to produce and comprehend syntactic structures, a condition typically referred to as "agrammatism." The neural correlates of agrammatism remain disputed in the literature, and distributed areas have been implicated as important predictors of performance, for example, Broca's area, anterior temporal areas, and temporo-parietal areas. We examined the association between damage to specific language-related ROIs and impaired syntactic processing in acute aphasia. We hypothesized that damage to the posterior middle temporal gyrus, and not Broca's area, would predict syntactic processing abilities. One hundred four individuals with acute aphasia (<20 days poststroke) were included in the study. Structural MRI scans were obtained, and all participants completed a 45-item sentence-picture matching task. We performed an ROI-based stepwise regression analyses to examine the relation between cortical brain damage and impaired comprehension of canonical and noncanonical sentences. Damage to the posterior middle temporal gyrus was the strongest predictor for overall task performance and performance on noncanonical sentences. Damage to the angular gyrus was the strongest predictor for performance on canonical sentences, and damage to the posterior superior temporal gyrus predicted noncanonical scores when performance on canonical sentences was included as a cofactor. Overall, our models showed that damage to temporo-parietal and posterior temporal areas was associated with impaired syntactic comprehension. Our results indicate that the temporo-parietal area is crucially implicated in complex syntactic processing, whereas the role of Broca's area may be complementary.

Brain-Derived Neurotrophic Factor Genotype-Specific Differences in Cortical Activation in Chronic Aphasia.

Purpose The brain-derived neurotrophic factor (BDNF) gene has been shown to be important for synaptic plasticity in animal models. Human research has suggested that BDNF genotype may influence stroke recovery. Some studies have suggested a genotype-specific motor-related brain activation in stroke recovery. However, recovery from aphasia in relation to BDNF genotype and language-related brain activation has received limited attention. We aimed to explore functional brain activation by BDNF genotype in individuals with chronic aphasia. Consistent with findings in healthy individuals and individuals with poststroke motor impairment, we hypothesized that, among individuals with aphasia, the presence of the Met allele of the BDNF gene is associated with reduced functional brain activation compared to noncarriers of the Met allele. Method Eighty-seven individuals with chronic stroke-induced aphasia performed a naming task during functional magnetic resonance imaging scanning and submitted blood or saliva samples for BDNF genotyping. The mean number of activated voxels was compared between groups, and group-based activation maps were directly compared. Neuropsychological testing was conducted to compare language impairment between BDNF genotype groups. The Western Aphasia Battery Aphasia Quotient (Kertesz, 2007) was included as a covariate in all analyses. Results While lesion size was comparable between groups, the amount of activation, quantified as the number of activated voxels, was significantly greater in noncarriers of the Met allele (whole brain: 98,500 vs. 28,630, p < .001; left hemisphere only: 37,209 vs. 7,000, p < .001; right hemisphere only: 74,830 vs. 30,630, p < .001). This difference was most strongly expressed in the right hemisphere posterior temporal area, pre- and postcentral gyrus, and frontal lobe, extending into the white matter. Correspondingly, the atypical BDNF genotype group was found to have significantly less severe aphasia (Western Aphasia Battery Aphasia Quotient of 64.2 vs. 54.3, p = .033) and performed better on a naming task (Philadelphia Naming Test [Roach, Schwartz, Martin, Grewal, & Brecher, 1996] score of 74.7 vs. 52.8, p = .047). A region of interest analysis of intensity of activation revealed no group differences, and a direct comparison of average activation maps across groups similarly yielded null results. Conclusion BDNF genotype mediates cortical brain activation in individuals with chronic aphasia. Correspondingly, individuals carrying the Met allele present with more severe aphasia compared to noncarriers. These findings warrant further study into the effects of BDNF genotype in aphasia. Supplemental Material https://doi.org/10.23641/asha.10073147 Presentation Video https://doi.org/10.23641/asha.10257581.

Long-range fibre damage in small vessel brain disease affects aphasia severity.

We sought to determine the underlying pathophysiology relating white matter hyperintensities to chronic aphasia severity. We hypothesized that: (i) white matter hyperintensities are associated with damage to fibres of any length, but to a higher percentage of long-range compared to mid- and short-range intracerebral white matter fibres; and (ii) the number of long-range fibres mediates the relationship between white matter hyperintensities and chronic post-stroke aphasia severity. We measured the severity of periventricular and deep white matter hyperintensities and calculated the number and percentages of short-, mid- and long-range white matter fibres in 48 individuals with chronic post-stroke aphasia. Correlation and mediation analyses were performed to assess the relationship between white matter hyperintensities, connectome fibre-length measures and aphasia severity as measured with the aphasia quotient of the Western Aphasia Battery-Revised (WAB-AQ). We found that more severe periventricular and deep white matter hyperintensities correlated with a lower proportion of long-range fibres (r = -0.423, P = 0.003 and r = -0.315, P = 0.029, respectively), counterbalanced by a higher proportion of short-range fibres (r = 0.427, P = 0.002 and r = 0.285, P = 0.050, respectively). More severe periventricular white matter hyperintensities also correlated with a lower proportion of mid-range fibres (r = -0.334, P = 0.020), while deep white matter hyperintensities did not correlate with mid-range fibres (r = -0.169, P = 0.250). Mediation analyses revealed: (i) a significant total effect of periventricular white matter hyperintensities on WAB-AQ (standardized beta = -0.348, P = 0.008); (ii) a non-significant direct effect of periventricular white matter hyperintensities on WAB-AQ (P > 0.05); (iii) significant indirect effects of more severe periventricular white matter hyperintensities on worse aphasia severity mediated in parallel by fewer long-range fibres (effect = -6.23, bootstrapping: standard error = 2.64, 95%CI: -11.82 to -1.56) and more short-range fibres (effect = 4.50, bootstrapping: standard error = 2.59, 95%CI: 0.16 to 10.29). We conclude that small vessel brain disease seems to affect chronic aphasia severity through a change of the proportions of long- and short-range fibres. This observation provides insight into the pathophysiology of small vessel brain disease, and its relationship with brain health and chronic aphasia severity.

Neuroanatomical structures supporting lexical diversity, sophistication, and phonological word features during discourse.

Deficits in lexical retrieval are commonly observed in individuals with post-stroke aphasia. Successful lexical retrieval is related to lexical diversity, lexical sophistication, and phonological word properties; however, the crucial brain regions supporting these different features are not fully understood. We performed MRI-based lesion symptom mapping in 58 individuals with a chronic left hemisphere stroke to assess how regional damage relates to spoken discourse-extracted measures of lexical diversity, lexical sophistication, and phonological word properties. For discourse transcription and word feature analysis, we used the Computerized Language Analysis (CLAN) program, Stanford Core Natural Language Processing, Irvine Phonotactic Online Dictionary, Lexical Complexity Analyzer, and Gramulator. Lesions involving the left posterior insula and supramarginal gyri and inferior fronto-occipital fasciculus were significant predictors of utterances with, on average, lower lexical diversity. Low lexical sophistication was associated with damage to the left pole of the superior temporal gyrus. Production of words with lower phonological complexity (fewer phonemes, higher phonological similarity) was associated with damage to the left supramarginal gyrus. Our findings indicate that discourse-extracted features of lexical retrieval depend on the integrity of specific brain regions involving insular and peri-Sylvian areas. The identified regions provide insight into potentially underlying mechanisms of lexically diverse, sophisticated and phonologically complex words produced during discourse.

Leukoaraiosis Is Associated With a Decline in Language Abilities in Chronic Aphasia.

Background. A fraction of stroke survivors with chronic aphasia experience declines in language abilities over time, but the reason for this remains unclear. Objective. To evaluate the effect of leukoaraiosis on baseline aphasia severity and long-term changes in aphasia severity. This study directly compares the predictive capacity of leukoaraiosis severity to that of lesion damage, a factor known to account for a substantial proportion of variance in the degree of language impairment and recovery. Methods. Using a longitudinal database of behavioral and neuroimaging data from 35 individuals in the chronic stage of recovery after a single-event left-hemisphere stroke (9 females, mean stroke age = 55.8 ± 9.1 years, mean months poststroke at initial evaluation = 36.3 ± 40.8), we examined 2 lines of inquiry: (1) to what extent does leukoaraiosis severity at initial evaluation predict aphasia severity and (2) to what extent does leukoaraiosis severity at initial evaluation predict longitudinal change in aphasia severity. Participants underwent high-resolution magnetic resonance imaging for the purpose of lesion volume analysis and leukoaraiosis severity rating. Biographical information was also considered. Results. Lesion volume and time poststroke at initial assessment best predicted initial aphasia severity (adjusted R2 = 0.37). Leukoaraiosis severity and initial aphasia severity significantly predicted decline in language abilities at follow-up, accounting for approximately one-third of the variance (adjusted R2 = 0.33). More severe leukoaraiosis was associated with a 4.3 odds increase of decline. Conclusions. Leukoaraiosis is a significant risk factor for declining language abilities in aphasia and should be considered for better identification of individuals at risk for long-term decline, which can guide clinical decision making.