Nonlinguistic cognitive impairment in poststroke aphasia: a prospective study

Language and executive functions in patients with transcortical motor aphasia and Broca's aphasia

This study investigated language and executive functions (EF) in people with transcortical motor aphasia (TMA) and Broca's aphasia (BA). Participants included 19 patients with TMA, 19 patients with BA, and 25 healthy controls. Verbal Fluency tests, Stroop tests and Trail-Making tests were administered to all participants, and the Boston Diagnostic Aphasia Examination (BDAE) was administered to participants with aphasia. Results showed that (1) both groups of patients with aphasia had poorer performance on Verbal Fluency tests, Stroop tests and Trail-Making tests than healthy controls; (2) participants with BA had superior performance on Stroop tests and Trail-Making tests, but not on Verbal Fluency tests, than participants with TMA, and (2) the performance on Verbal Fluency tests, Stroop tests and Trail-Making was significantly correlated with the performance on BDAE for participants with TMA, but not for participants with BA. These results suggest that EF deficits are present in both patients with TMA and those with BA. They also show that the relationship between EF deficits and language impairments in people with aphasia might depend on the type of aphasia, aspects of language, and the components of EF measured.

A multitasking assessment for aphasia: The Catalog Ordering Task

Multitasking assessments based on everyday scenarios are useful assessment tools that can reveal the consequences of language and cognitive impairments on functioning. Unfortunately, many existing multitasking assessments require a high degree of linguistic processing that may preclude their use with adults with aphasia. The purposes of this paper are to (1) describe the development of a multitasking assessment relevant to everyday activities, the Catalog Ordering Task (COT), specifically designed for aphasia, (2) investigate differences between the performances of adults without aphasia and adults with aphasia on the COT, and (3) explore the relationships between language and cognitive performances and the COT to facilitate clinical utility. Seventy-four participants, 40 adults with aphasia and 34 people without aphasia, completed the multitasking assessment in single and dual task conditions. The secondary task in the dual task condition was a tone detection task requiring a foot-pedal press. Participants with aphasia also completed additional language and cognitive assessments. We systematically developed the Catalog Ordering Test (COT) with considerations for semantics, syntax, and ecological validity. Criterion validity with acceptable levels of inter-rater and test-retest reliability were observed. Adults with aphasia performed with about half the accuracy and twice as slowly as people without aphasia. Adults with all severity levels of aphasia were able to complete the COT. Multitasking performance on the COT was related to impairment-level measures of language and cognition. The COT is a potentially clinically useful assessment of multitasking, specially designed for aphasia.

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.

Combining executive function training and anomia therapy in chronic post-stroke aphasia: A preliminary study of multidimensional effects

PURPOSE

The influential relationship between executive functioning and aphasia rehabilitation outcomes has been addressed in a number of studies, but few have studied the effect of adding executive function training to linguistic therapies. The present study aimed to measure the effects of combining, within therapy sessions, executive function training and anomia therapy on naming and discourse abilities in people with chronic aphasia.

METHOD

A single-case experimental design with multiple baselines across participants was used. Four persons with chronic post-stroke aphasia received 12 sessions of a tailored treatment combining executive function training and semantic feature analysis (SFA) therapy. Naming accuracy of treated items was examined over the course of the treatment while control naming scores of untreated items and discourse measures were collected pre-treatment, immediately post-treatment, and 4 weeks post-treatment, in order to investigate the multidimensional effects of the treatment and their maintenance.

RESULT

Naming skills improved in all participants for treated and untreated items, were maintained over time, and were accompanied by improved discourse abilities. Visual and statistical analyses showed a significant treatment effect for naming skills in three out of the four participants.

CONCLUSION

A combination of executive function training and SFA treatment in people with chronic aphasia may improve both naming skills and discourse efficiency. Further studies are needed to substantiate these promising preliminary results.

Generalization in Aphasia Treatment: A Tutorial for Speech-Language Pathologists

PURPOSE

Generalization has been defined and instantiated in a variety of ways over the last half-century, and this lack of consistency has created challenges for speech-language pathologists to plan for, implement, and measure generalization in aphasia treatment protocols. This tutorial provides an overview of generalization with a focus on how it relates to aphasia intervention, including a synthesis of existing principles of generalization and examples of how these can be embedded in approaches to aphasia treatment in clinical and research settings.

METHOD

Three articles collectively listing 20 principles of generalization formed the foundation for this tutorial. The seminal work of Stokes and Baer (1977) focused attention on generalization in behavioral change following treatment. Two aphasia-specific resources identified principles of generalization in relation to aphasia treatment (Coppens & Patterson, 2018; Thompson, 1989). A selective literature review was conducted to identify evidence-based examples of each of these 20 principles from the extant literature.

RESULTS

Five principles of generalization were synthesized from the original list of 20. Each principle was supported by studies drawn from the aphasia treatment literature to exemplify its application.

CONCLUSIONS

Generalization is an essential aspect of meaningful aphasia intervention. Successful generalization requires the same dedication to strategic planning and outcome measurement as the direct training aspect of intervention. Although not all people with aphasia are likely to benefit equally from each of the principles reviewed herein, our synthesis provides information to consider for maximizing generalization of aphasia treatment outcomes.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24714399.

Looking Upstream to Understand Race/Ethnicity as a Moderator for Poststroke Neuroinflammation and a Social Determinant for Poststroke Aphasia Outcomes

INTRODUCTION

Over the past decade, the stroke literature has begun to acknowledge and explore explanations for longstanding racial/ethnic differences in stroke outcomes. Poststroke cognitive impairment (PSCI) and poststroke aphasia are two such negative poststroke outcomes where racial/ethnic differences exist. Physiological differences, such as stroke type and lesion size, have been used to partially explain the variation in PSCI and aphasia. However, there is some evidence, although limited, that suggests neuroinflammatory processes as part of allostatic load may be a key contributor to the observed disparities.

METHOD

In this tutorial, we explore the influence of race differences in inflammation on poststroke cognitive outcomes. We suggest lifetime stress and other external determinants of health such as neighborhood environment and discriminatory practices through "weathering" explain differences in inflammation. While using an allostatic load framework, we explore the literature focusing specifically on the role of neuroinflammation on poststroke outcomes.

CONCLUSIONS

Examination of the immune response poststroke provides a foundation for understanding the mechanisms of PSCI and poststroke aphasia and the potential contributions of neuroinflammatory processes on poststroke cognitive outcomes. Furthermore, understanding of racial differences in those processes may contribute to a better understanding of racial disparities in general stroke outcomes as well as poststroke aphasia.

An electrophysiological and behavioral investigation of feedback-based learning in aphasia

Introduction

Feedback is a fundamental aspect of aphasia treatments. However, learning from feedback is a cognitively demanding process. At the most basic level, individuals must detect feedback and extract outcome-related information (i.e., feedback processing). Neuroanatomical and neuropsychological differences associated with post-stroke aphasia may influence feedback processing and potentially how people with aphasia (PWA) respond to feedback-based treatments. To better understand how post-stroke aphasia affects feedback-based learning, the current study leverages event-related potentials (ERPs) to (1) characterize the relationship between feedback processing and learning, (2) identify cognitive skills that are associated with feedback processing, and (3) identify behavioural correlates of feedback-based learning in PWA.

Methods

Seventeen PWA completed a feedback-based novel word learning task. Feedback processing was measured using the feedback-related negativity (FRN), an ERP hypothesized to reflect the detection and evaluation of outcomes communicated via feedback. Individuals also completed neuropsychological assessments of language (phonological processing, verbal short-term memory) and executive functioning.

Results

PWA elicited an FRN that was sensitive to feedback valence. The magnitude of the FRN was not associated with novel word learning but was strongly correlated with performance on another feedback-based task, the Berg Card Sort. Cognitive variables (information updating, selective attention) but not language variables were associated with novel word learning.

Discussion & Conclusion

For PWA, feedback processing may be associated with learning in some but not all feedback-based contexts. These findings may inform future research in determining which variables moderate the relationship between feedback processing and learning with the long-term goal of identifying how feedback can be modified to support successful learning during aphasia rehabilitation.

Dual tasking in individuals with post-stroke aphasia: a scoping review protocol

OBJECTIVE

The purpose of this scoping review is to identify the main theoretical frameworks being used to explain dual-task performance deficits in people with post-stroke aphasia, to identify the domains of function being measured and the assessments being used, to highlight current interventions to improve dual-task performance, and to identify the gaps in the current body of literature on dual tasking and aphasia.

INTRODUCTION

Post-stroke aphasia can lead to challenges across all activities of daily living. However, little is known about how a stroke and co-occurring language impairment may affect the allocation of cognitive resources, particularly in dual-task conditions. This vital information will allow researchers and clinicians to develop more effective interventions to combat the effects of the infarct.

INCLUSION CRITERIA

To be considered in the review, articles must be written in English, include individuals at least 6 months post stroke, include adults with aphasia (with data presented separately from other populations), and include measures of dual-task performance.

METHODS

This review will be conducted in line with the JBI methodology for scoping reviews. A search of Linguistics and Language Behavior Abstracts, PsycINFO, Communication Mass Media Complete, PubMed, CINAHL Plus, ScienceDirect, and the Cochrane Library will be undertaken to identify publications on the topic. Results will be restricted to sources that meet the inclusion/exclusion criteria. Data will be extracted from included papers by up to 3 independent reviewers using a data extraction tool developed by the reviewers. The results will be presented as a narrative summary, accompanied by charted results, as appropriate.

REVIEW REGISTRATION

Open Science Framework https://osf.io/2yx76.

Cognitive training incorporating temporal information processing improves linguistic and non-linguistic functions in people with aphasia

People with aphasia (PWA) often present deficits in non-linguistic cognitive functions, such as executive functions, working memory, and temporal information processing (TIP), which intensify the associated speech difficulties and hinder the rehabilitation process. Therefore, training targeting non-linguistic cognitive function deficiencies may be useful in the treatment of aphasia. The present study compared the effects of the novel Dr. Neuronowski® training method (experimental training), which particularly emphasizes TIP, with the linguistic training commonly applied in clinical practice (control training). Thirty four PWA underwent linguistic and non-linguistic assessments before and after the training as well as a follow-up assessment. Patients were randomly assigned to either experimental (n = 18) or control groups (n = 16). The experimental training improved both non-linguistic functions (TIP and verbal short-term and working memory) and linguistic functions: phoneme discrimination, sentence comprehension, grammar comprehension, verbal fluency, and naming. In contrast, the control training improved only grammar comprehension and naming. The follow-up assessment confirmed the stability of the effects of both trainings over time. Thus, in PWA, Dr. Neuronowski® training appears to have broader benefits for linguistic and non-linguistic functions than does linguistic training. This provides evidence that Dr. Neuronowski® may be considered a novel tool with potential clinical applications.

Mapping spoken language and cognitive deficits in post-stroke aphasia

Aphasia is an acquired disorder caused by damage, most commonly due to stroke, to brain regions involved in speech and language. While language impairment is the defining symptom of aphasia, the co-occurrence of non-language cognitive deficits and their importance in predicting rehabilitation and recovery outcomes is well documented. However, people with aphasia (PWA) are rarely tested on higher-order cognitive functions, making it difficult for studies to associate these functions with a consistent lesion correlate. Broca's area is a particular brain region of interest that has long been implicated in speech and language production. Contrary to classic models of speech and language, cumulative evidence shows that Broca's area and surrounding regions in the left inferior frontal cortex (LIFC) are involved in, but not specific to, speech production. In this study we aimed to explore the brain-behaviour relationships between tests of cognitive skill and language abilities in thirty-six adults with long-term speech production deficits caused by post-stroke aphasia. Our findings suggest that non-linguistic cognitive functions, namely executive functions and verbal working memory, explain more of the behavioural variance in PWA than classical language models imply. Additionally, lesions to the LIFC, including Broca's area, were associated with non-linguistic executive (dys)function, suggesting that lesions to this area are associated with non-language-specific higher-order cognitive deficits in aphasia. Whether executive (dys)function - and its neural correlate in Broca's area - contributes directly to PWA's language production deficits or simply co-occurs with it, adding to communication difficulties, remains unclear. These findings support contemporary models of speech production that place language processing within the context of domain-general perception, action and conceptual knowledge. An understanding of the covariance between language and non-language deficits and their underlying neural correlates will inform better targeted aphasia treatment and outcomes.

Depression Risk in Post-Stroke Aphasia Patients: A Nationwide Population-Based Cohort Study

INTRODUCTION

Depression and aphasia impair the quality of life after a stroke. Studies linking depression risk to post-stroke aphasia (PSA) lacked confirmation using a large database.

METHODS

Using Taiwan's National Health Insurance claims data, we identified ≥18-year-old patients hospitalized for stroke from 2005 to 2009, and those diagnosed with aphasia during hospitalization or within 3 months after discharge were selected to form the aphasic group. We estimated depression incidence by December 31, 2018, and used the Cox proportional hazards model to estimate aphasia group to non-aphasia group hazard ratios (HRs).

RESULTS

With a median follow-up period of 7.91 and 8.62 years for aphasia (n = 26,754) and non-aphasia groups (n = 139,102), respectively, the incidence of depression was higher in the aphasia group than in the non-aphasia group (9.02 vs. 8.13 per 1,000 person-years), with an adjusted HR (95% confidence intervals [CI]) of 1.21 (1.15-1.29) for depression. The adjusted HRs (95% CI) of depression were homogenous for females, 1.26 (1.15-1.37); for males, 1.18 (1.09-1.27); for hemorrhagic stroke, 1.22 (1.09-1.37); and for ischemic stroke, 1.21 (1.13-1.30). Results in analyzing 25,939 propensity score-matched pairs demonstrated an equivalent effect.

CONCLUSION

Patients with PSA are at an increased risk of developing depression, regardless of sex or stroke type.

Attention to attention in aphasia - elucidating impairment patterns, modality differences and neural correlates

It is increasingly acknowledged that patients with aphasia following a left-hemisphere stroke often have difficulties in other cognitive domains. One of these domains is attention, the very fundamental ability to detect, select, and react to the abundance of stimuli present in the environment. Basic and more complex attentional functions are usually distinguished, and a variety of tests has been developed to assess attentional performance at a behavioural level. Attentional performance in aphasia has been investigated previously, but often only one specific task, stimulus modality, or type of measure was considered and usually only group-level analyses or data based on experimental tasks were presented. Also, information on brain-behaviour relationships for this cognitive domain and patient group is scarce. We report detailed analyses on a comprehensive dataset including patients' performance on various subtests of two well-known, standardised neuropsychological test batteries assessing attention. These tasks allowed us to explore: 1) how many patients show impaired performance in comparison to normative data, in which tasks and on what measure; 2) how the different tasks and measures relate to each other and to patients' language abilities; 3) the neural correlates associated with attentional performance. Up to 32 patients with varying aphasia severity were assessed with subtests from the Test of Attentional Performance (TAP) as well as the Test of Everyday Attention (TEA). Performance was compared to normative data, relationships between attention measures and other background data were explored with principal component analyses and correlations, and brain-behaviour relationships were assessed by means of voxel-based correlational methodology. Depending on the task and measure, between 3 and 53 percent of the patients showed impaired performance compared to normative data. The highest proportion of impaired performance was noted for complex attention tasks involving auditory stimuli. Patients differed in their patterns of performance and only the performance in the divided attention tests was (weakly) associated with their overall language impairment. Principal components analyses yielded four underlying factors, each being associated with distinct neural correlates. We thus extend previous research in characterizing different aspects of attentional performance within one sample of patients with chronic post stroke aphasia. Performance on a broad range of attention tasks and measures was variable and largely independent of patients' language abilities, which underlines the importance of assessing this cognitive domain in aphasic patients. Notably, a considerable proportion of patients showed difficulties with attention allocation to auditory stimuli. The reasons for these potentially modality-specific difficulties are currently not well understood and warrant additional investigations.

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

INTRODUCTION

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Short-term memory and sentence comprehension in Catalan aphasia

The main goal of the present study is to investigate visual and verbal short-term memory side to side with sentence comprehension in Catalan-speaking subjects with aphasia in comparison with subjects without brain damage. We aim to examine whether there are any significant correlations between their performance on short-term memory and comprehension tasks in order to evaluate the hypothesis that linguistic and memory deficits in aphasia are the result of a dysfunction of a common mechanism, usually short-term memory. Eigthy-four control subjects and twelve individuals suffering from different types of aphasia were assessed using the Catalan version of the Comprehensive Aphasia Test (CAT-CAT), which includes one recognition task and two digit and word span tests to evaluate visual and verbal short-term memory, respectively, as well as a sentence-to-picture comprehension task. The results showed that the performance of subjects with aphasia was significantly low on all tasks. Yet, the logistic regression analysis revealed that the magnitude of the differences between the control and experimental group varied across subtests, and that visual short-term memory was better preserved than verbal memory. The results also showed that there were no significant correlations between memory and language comprehension, which rules out the hypothesis that the deficits observed are due to a common underlying mechanism. Individual variation was also observed, specially on memory subtests, which suggest that memory impairments cannot explain the comprehension deficit in aphasia.

Does Executive Function Training Impact on Communication? A Randomized Controlled tDCS Study on Post-Stroke Aphasia

New approaches in aphasia rehabilitation have recently identified the crucial role of executive functions (EFs) in language recovery, especially for people with severe aphasia (PWSA). Indeed, EFs include high-order cognitive abilities such as planning and problem solving, which enable humans to adapt to novel situations and are essential for everyday functional communication. In a randomized double-blind crossover design, twenty chronic Italian PWSA underwent ten days of transcranial direct current stimulation (tDCS) (20 min, 2 mA) over the right dorsolateral prefrontal cortex (DLPFC). Two conditions were considered, i.e., anodal and sham, while performing four types of cognitive training (alertness, selective attention, visuo-spatial working memory, and planning), all of which were related to executive functions. After anodal tDCS, a greater improvement in selective attention, visuospatial working memory and planning abilities was found compared to the sham condition; this improvement persisted one month after the intervention. Importantly, a significant improvement was also observed in functional communication, as measured through the Communication Activities of Daily Living Scale, in noun and verb naming, in auditory and written language comprehension tasks and in executive function abilities. This evidence emphasizes, for the first time, that tDCS over the right DLPFC combined with executive training enhances functional communication in severe aphasia.

Research trends of the neuroimaging in aphasia: A bibliometric analysis and visualization analysis from 2004 to 2021

Objectives

To review the current research status of the neuroimaging of aphasia, and reveal the hotspots and frontiers of research in this field.

Methods

We searched articles related to the neuroimaging research on aphasia since Web of Science (WOS) database construction and extracted the data. CiteSpace and VOSviewer were used for the country/institution analysis, journal analysis, discipline analysis, burst keyword analysis and cited-reference cluster analysis.

Results

Of the studies retrieved from WOS, 2922 studies that related to the neuroimaging of aphasia were screened and finally included 2799 articles for research. The United States of America and University of California San Francisco were the main countries and institutions in this field. Brain had the highest impact factor in both published and cited journals. Through the discipline and topic analysis of this field, the most common category was Neurosciences and Neurology. The keyword with the strongest citation strength was “functional connectivity,” and the recent burst keywords were “functional connectivity” and “network.” The co-citation network showed seven clusters greater than 100. Among the top 5 clusters, the most recently formed cluster, Cluster #2 (progressive supranuclear palsy), had an average year of 2017. The literature in the top 5 clusters mainly focused on 3 aspects, specifically, the discovery of language processing models, injury and recovery mechanisms of post-stroke aphasia (PSA), and diagnosis of primary progressive aphasia (PPA) variants.

Conclusion

The results of this bibliometric study revealed the following three research hotspots in the neuroimaging of aphasia: clarifying the connotation of the most recognized language processing model, the dual-stream model, exploring the injury mechanism based on the dual-stream model and the recovery mechanism involving the left and right hemispheres of PSA, and determining the diagnostic criteria for PPA variants. A major research trend is to combine new neuroimaging technology, such as PET tracer technology, to realize the visual presentation of disease-specific proteins to improve the pathological diagnostic criteria of PPA variants. Accordingly, a visualized analysis of literature that uses CiteSpace provides a more rapid, repeatable and flexible method, which is more conducive to capturing research hotspots and emerging trends.

Predictors of functional communication in people with aphasia after stroke

BACKGROUND

Aphasia, the most common language disorder secondary to stroke, has been associated with increased mortality, longer hospitalization and rehabilitation times, worse performance in daily activities, increased financial burden, and short- and long-term complications. Aphasia can negatively impact functional communication skills, including social networks, social activities, relationships with other people and social support.

OBJECTIVE

To evaluate patients with poststroke aphasia in their respective residences to investigate potential predictors of functional communication.

METHODS

The prospective cohort included patients with poststroke aphasia aged 18 years or older who resided in the city of Salvador, Northeastern Brazil. Following discharge from the Stroke Unit (SU), the individuals themselves, or their guardians, were contacted by telephone to schedule a home visit no less than three months after discharge. At baseline, sociodemographic and clinical data were collected, in addition to the scores on the National Institutes of Health Stroke Scale (NIHSS) and modified Barthel Index (mBI). The American Speech-Language-Hearing Association Functional Assessment of Communication Skills for Adults (ASHA FACS) was applied at the patients' homes. Multivariate linear regression was employed using the total score on the ASHA FACS as the outcome of interest.

RESULTS

A multivariate analysis of the associated factors identified using the linear regression revealed that only functional capacity (as assessed by the mBI) upon discharge from the SU remained as an independent predictor of functional communication performance (β = 0.042; 95% confidence interval [95%CI] = 0.013-0.071; p = 0.002).

CONCLUSION

The functional capacity to perform daily activities, evaluated upon discharge from a stroke unit, was identified as a potential predictor of functional communication performance, regardless of the time elapsed after the stroke.

Does acupuncture therapy improve language function of patients with aphasia following ischemic stroke? A systematic review and meta-analysis

BACKGROUND

Aphasia is one of the most common complications in patients with ischemic stroke. Studies have shown that acupuncture can improve the symptoms of aphasia patients. However, the effect of acupuncture on language function in patients with ischemic stroke is still controversial.

OBJECTIVE

This study aimed to critically assess the efficacy and safety of acupuncture for aphasia following ischemic stroke.

METHODS

PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science Core Collection, China National Knowledge Infrastructure, Wanfang Digital Periodicals, and Chinese Science and Technology Periodicals database were searched. All randomized controlled trials (RCTs) that met the criteria were included.

RESULTS

Meta-analyses showed that mean difference in change of auditory comprehension score (MD = 7.71, 95% CI: 1.83 to 13.59, P = 0.01), spontaneous speech (MD = 2.77, 95% CI: 0.59 to 4.95, P = 0.01), repetition score (MD = 14.48, 95% CI: 11.04 to 17.91, P <  0.00001) and naming score (MD = 14.60, 95% CI: 11.33 to 17.88, P <  0.00001) measured by WAB scale were statistically significant. Subgroup analyses demonstrated that there were statistically significant mean differences in four items of WAB scale in patients with sub-acute stroke, and no statistically significant differences in patients with acute stroke.

CONCLUSION

The present study suggests that acupuncture may improve the language function of patients with aphasia following ischemic stroke, especially during the sub-acute phase. However, due to insufficient sample sizes and information on the safety, more high-quality RCTs are still needed.

Assessing executive functions in post-stroke aphasia-utility of verbally based tests

It is increasingly acknowledged that, often, patients with post-stroke aphasia not only have language impairments but also deficits in other cognitive domains (e.g. executive functions) that influence recovery and response to therapy. Many assessments of executive functions are verbally based and therefore usually not administered in this patient group. However, the performance of patients with aphasia in such tests might provide valuable insights both from a theoretical and clinical perspective. We aimed to elucidate (i) if verbal executive tests measure anything beyond the language impairment in patients with chronic post-stroke aphasia, (ii) how performance in such tests relates to performance in language tests and nonverbal cognitive functions, and (iii) the neural correlates associated with performance in verbal executive tests. In this observational study, three commonly used verbal executive tests were administered to a sample of patients with varying aphasia severity. Their performance in these tests was explored by means of principal component analyses, and the relationships with a broad range of background tests regarding their language and nonverbal cognitive functions were elucidated with correlation analyses. Furthermore, lesion analyses were performed to explore brain-behaviour relationships. In a sample of 32 participants, we found that: (i) a substantial number of patients with aphasia were able to perform the verbal executive tests; (ii) variance in performance was not explained by the severity of an individual's overall language impairment alone but was related to two independent behavioural principal components per test; (iii) not all aspects of performance were related to the patient's language abilities; and (iv) all components were associated with separate neural correlates, some overlapping partly in frontal and parietal regions. Our findings extend our clinical and theoretical understanding of dysfunctions beyond language in patients with aphasia.

A Mobile-based Virtual Reality Speech Rehabilitation App for Patients With Aphasia After Stroke: Development and Pilot Usability Study

Background

Stroke has the highest disability-adjusted life-years lost in any disease, and approximately one-third of the patients get aphasia. Computers and tablets are innovative and aid in intensive treatments in speech rehabilitation for patients with aphasia. However, mechanical training limits the help to patients.

Objective

This study aims to provide a framework for an integrated virtual reality (VR) app to provide speech rehabilitation for patients with aphasia.

Methods

The content was generated through an in-depth literature review and discussion with experienced rehabilitation physicians and occupational therapists. We then conducted a 2-round Delphi study with 15 experts from hospitals and universities to rate the content using a 5-point Likert scale. The app was developed by an interdisciplinary team involving VR, medical science of rehabilitation, and therapeutic rehabilitation. Pilot usability testing of this novel app was conducted among 5 patients with aphasia, 5 healthy volunteers, 5 medical staff, and 2 VR experts.

Results

We designed 4 modules of speech rehabilitation: oral expression, auditory comprehension, cognition, and comprehensive application. Our VR-based interactive and intelligent app was developed to provide an alternative option for patients with aphasia. Pilot usability testing revealed user satisfaction with the app.

Conclusions

This study designed and tested a novel VR-based app for speech rehabilitation specifically adapted to patients with aphasia. This will guide other studies to develop a similar program or intelligent system in a clinical setting.

Executive control deficits and lesion correlates in acute left hemisphere stroke survivors with and without aphasia

In contrast to the traditional definition of the disorder, many individuals with aphasia exhibit non-linguistic cognitive impairments, including executive control deficits. Classic lesion studies cite frontal lobe damage in executive dysfunction, but more recent lesion symptom-mapping studies in chronic aphasia present mixed results. In this study, we compared executive control abilities of acute stroke survivors with and without aphasia and investigated lesion correlates of linguistic and non-linguistic cognitive tasks. Twenty-nine participants with acute left hemisphere stroke resulting in aphasia (n = 14) or no aphasia (n = 15) completed clinical MRI and testing, including three NIH Toolbox Cognition Batteries (Pattern Comparison Processing Speed, Flanker Inhibitory Control and Attention, and Dimensional Change Card Sort Tests) and the Boston Naming Test. We compared performance between groups using Wilcoxon rank sum tests. We used Least Absolute Shrinkage and Selection Operator Regression to identify neural markers (percent regional damage, hypoperfusion within vascular territories, and total lesion volume) of executive control deficits and anomia. Group performance was comparable on the Pattern Comparison Processing Speed Test, but people with aphasia had poorer standard scores, lower accuracy, and slower response times on the Dimensional Change Card Sort Test than people without aphasia. Damage to extrasylvian regions (dorsolateral prefrontal cortex, intraparietal sulcus) was related to executive control deficits, whereas language network damage (to inferior frontal and superior and posterior middle temporal gyri) was linked to naming impairments. These results suggest people with aphasia can exhibit comorbid executive control impairments linked to damage outside classic language network areas.

What is Functional Communication? A Theoretical Framework for Real-World Communication Applied to Aphasia Rehabilitation

Aphasia is an impairment of language caused by acquired brain damage such as stroke or traumatic brain injury, that affects a person’s ability to communicate effectively. The aim of rehabilitation in aphasia is to improve everyday communication, improving an individual’s ability to function in their day-to-day life. For that reason, a thorough understanding of naturalistic communication and its underlying mechanisms is imperative. The field of aphasiology currently lacks an agreed, comprehensive, theoretically founded definition of communication. Instead, multiple disparate interpretations of functional communication are used. We argue that this makes it nearly impossible to validly and reliably assess a person’s communicative performance, to target this behaviour through therapy, and to measure improvements post-therapy. In this article we propose a structured, theoretical approach to defining the concept of functional communication. We argue for a view of communication as “situated language use”, borrowed from empirical psycholinguistic studies with non-brain damaged adults. This framework defines language use as: (1) interactive, (2) multimodal, and (3) contextual. Existing research on each component of the framework from non-brain damaged adults and people with aphasia is reviewed. The consequences of adopting this approach to assessment and therapy for aphasia rehabilitation are discussed. The aim of this article is to encourage a more systematic, comprehensive approach to the study and treatment of situated language use in aphasia.

Predicting home discharge after inpatient rehabilitation of stroke patients with aphasia

The early identification of the discharge setting from Inpatient Rehabilitation Facilities is a primary goal in stroke-related research because of its clinical and socio-economic relevance. Several features have been identified as significant predictors of the discharge setting. Within cognitive deficits, aphasia is known to be a common and disabling condition that could influence rehabilitation outcome. However, it is often set as an exclusion criterion in stroke research. This study aims to investigate the predictive power of clinical variables, in particular specific language disturbances and nonlinguistic cognitive deficits, for discharge setting in post-acute stroke patients with aphasia after intensive multidisciplinary rehabilitation. In a sample of 158 patients, demographic, motor, language, and nonverbal cognitive data were retrospectively considered for the prediction of the discharge to home vs. another institutional setting. Univariate analysis identified relevant differences between groups and the significant variables were included in a logistic regression model. The results showed that better functional motor status, absence of dysphagia and unimpaired nonlinguistic cognitive profile independently predict the discharge to home. In particular, nonverbal cognitive functioning seemed to be specifically relevant within the aphasic population. The findings could be helpful for setting up the rehabilitation priorities and an adequate discharge arrangement.

Translation and Cross-cultural Adaptation of the Aphasia Check List in Persian Speakers With Aphasia

Introduction:

The Aphasia Check List (ACL) is a comprehensive, time-saving tool for language evaluation in aphasia, including a cognitive assessment part. This cross-sectional study aimed to translate ACL into Persian and analyze the psychometric features of the translated version. The original version of the ACL was translated and adapted from German; its psychometric features were then determined.

Methods:

Twenty People With Aphasia (PWA) and 50 age- and education-matched, cognitively healthy controls participated in this research. Possible floor and ceiling effects, discriminant validity, test-retest reliability, and internal consistency of the test were analyzed in addition to the evaluation of internal correlations between the test parts (language & cognition).

Results:

Regarding the performance of PWAs in the language section and the cognitive subtests assessing attention, memory, and reasoning, there were no floor and ceiling effects. Adequate discriminant validities for the language section of the test [i.e., total score: (Mann-Whitney U= 6.000, P<0.001); diagnostic subtests scores: (Mann-Whitney U= 3.000, P<0.001), and each subtest individually. Besides, the attention subtest of the cognition section (Mann-Whitney U= 16.500, P<0.001) was also observed. There was no difference between the control and patient groups in the subtests of memory (Mann-Whitney U= 497.500, P=0.973) and reasoning (Mann-Whitney U= 3.000, P= 308). The test-retest reliability was acceptable in all subtests (ICC agreement= 0.573–0.984). The ACL-P suggested appropriate internal consistency (Cronbach’s alpha coefficient= 0.761 for test & retest scores). There were also significant correlations between language and cognition in the control and patient groups.

Conclusion:

The ACL-P test indicated sufficient reliability and validity for the evaluation of Persian-speaking PWAs and is suggested to be used in studies on this population.

Working Memory in Aphasia: The Role of Temporal Information Processing

Aphasia is an acquired impairment of language functions resulting from a brain lesion. It is usually accompanied by deficits in non-linguistic cognitive processes. This study aimed to investigate in patients with aphasia the complex interrelationships between selected cognitive functions: auditory speech comprehension, working memory (WM), and temporal information processing (TIP) in the millisecond time range. Thirty right-handed subjects (20 males) aged from 27 to 82 years suffering from post-stroke aphasia participated in the study. Verbal working memory (VWM) and spatial working memory (SWM) were assessed with: (1) a receptive verbal test and (2) the Corsi Block-Tapping Test, respectively. Both these WM tests used the forward tasks (mainly engaging maintenance processes, i.e., storing, monitoring, and matching information) and backward tasks (engaging both maintenance and manipulation processes, i.e., reordering and updating information). Auditory comprehension was assessed by receptive language tests, and TIP efficiency was assessed by auditory perception of temporal order in the millisecond time range. We observed better performance of forward WM tasks than backward ones, independently of the type of material used. Furthermore, the severity of auditory comprehension impairment correlated with the efficiency on both forward and backward VWM tasks and the backward SWM task. Further analysis revealed that TIP plays a crucial role only in the latter task. These results indicate the divergent pattern of interactions between WM and TIP depending on the type of WM tasks. Level of verbal competency appeared to play an important role in both VWM tasks, whereas TIP (which is associated with manipulation processes) appeared to be important for SWM, but only on the backward task.

The verbal, non-verbal and structural bases of functional communication abilities in aphasia

The ability to communicate, functionally, after stroke or other types of acquired brain injury is crucial for the person involved and the people around them. Accordingly, assessment of functional communication is increasingly used in large-scale randomized controlled trials as the primary outcome measure. Despite the importance of functional communication abilities to everyday life and their centrality to the measured efficacy of aphasia interventions, there is little knowledge about how commonly used measures of functional communication relate to each other, whether they capture and grade the full range of patients’ remaining communication skills and how these abilities relate to the patients’ verbal and non-verbal impairments as well as the underpinning lesions. Going beyond language-only factors is essential given that non-verbal abilities can play a crucial role in an individual’s ability to communicate effectively. This study, based on a large sample of patients covering the full range and types of post-stroke aphasia, addressed these important, open questions. The investigation combined data from three established measures of functional communication with a thorough assessment of verbal and non-verbal cognition as well as structural neuroimaging. The key findings included: (i) due to floor or ceiling effects, the full range of patients’ functional communication abilities was not captured by a single assessment alone, limiting the utility of adopting individual tests as outcome measures in randomized controlled trials; (ii) phonological abilities were most strongly related to all measures of functional communication and (iii) non-verbal cognition was particularly crucial when language production was relatively impaired and other modes of communication were allowed, when patients rated their own communication abilities, and when carers rated patients’ basic communication abilities. Finally, in addition to lesion load being significantly related to all measures of functional communication, lesion analyses showed partially overlapping clusters in language regions for the functional communication tests. Moreover, mirroring the findings from the regression analyses, additional regions previously associated with non-verbal cognition emerged for the Scenario Test and for the Patient Communication Outcome after Stroke rating scale. In conclusion, our findings elucidated the cognitive and neural bases of functional communication abilities, which may inform future clinical practice regarding assessments and therapy. In particular, it is necessary to use more than one measure to capture the full range and multifaceted nature of patients’ functional communication abilities and a therapeutic focus on non-verbal cognition might have positive effects on this important aspect of activity and participation.

Characteristics of Non-linguistic Cognitive Impairment in Post-stroke Aphasia Patients

Background: Non-linguistic cognitive training has been suggested to improve the communication skills of patients with post-stroke aphasia (PSA). However, the association between language and non-linguistic cognitive functions is not fully understood. In this study, we used the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) to evaluate the characteristics of non-linguistic cognitive impairments in Chinese PSA patients.

Methods: A total of 86 stroke patients were recruited in this study. Language and non-linguistic cognitive impairments were evaluated by the Western Aphasia Battery (WAB) and LOTCA, respectively. The patients were divided into two groups (PSA and non-PSA), and the Chinese norm (the data came from 44 Chinese individuals without neurological disorders in a previous study) was used as the control group. The LOTCA scores were compared among the three groups. Patients in the PSA group were subdivided into the fluent aphasia group (FAG) and the non-FAG according to the Chinese aphasia fluency characteristic scale. The LOTCA scores were also compared between the PSA subdivisions. Potential confounders were adjusted in the analysis of covariance. Partial correlation analysis between the subscores of WAB and LOTCA was also performed.

Results: The total LOTCA scores in the PSA group (75.11 ± 17.08) were significantly lower compared with scores in the non-PSA (96.80 ± 7.75, P < 0.001) and the control group (97.65 ± 16.24, P < 0.001). The PSA group also had lower orientation, visual perception (VP), spatial perception (SP), visuomotor organization, thinking operation, and attention scores. The total LOTCA, orientation, VP, SP, and MP scores were lower in the non-FAG (69.24 ± 18.06, 8.62 ± 5.09, 12.76 ± 2.47, 7.48 ± 3.01, and 9.62 ± 2.25, respectively) compared with the FAG (80.36 ± 14.07, 12.14 ± 3.99, 14.09 ± 1.93, 9.68 ± 3.01, 10.55 ± 1.63, respectively, P's < 0.05). The aphasia quotient was positively correlated with the total score of LOTCA and scores of orientation, VP, SP, and MP (r = 0.710, 0.744, 0.565, 0.597, and 0.616; P < 0.001).

Conclusion: Compared with stroke patients without aphasia, patients with PSA often have more extensive and serious non-linguistic cognitive impairments. Patients with non-fluent aphasia often present with serious cognitive impairments than those with fluent aphasia, especially the impairments of orientation and SP. Non-linguistic cognitive impairments correlate with language impairments in aphasia.

Intensive aphasia therapy improves low mood in fluent post-stroke aphasia: Evidence from a case-controlled study

Introduction: Depressive symptoms are a major drawback of aphasia, negatively impacting on functional outcomes. In a previous study, Intensive Language-Action Therapy (ILAT) was effective in improving depression and low mood in persons with chronic non-fluent aphasia. We present a proof-of-concept case-control study that evaluates language and mood outcomes amongst persons with fluent post-stroke aphasia.Participants: Thirteen Spanish speaking persons with fluent aphasia due to chronic stroke lesions in the left hemisphere participated in the study.Intervention: Five participants (intervention group) received ILAT for 3 h/day during two consecutive weeks, for an overall of 30 h, and 8 participants (control group) entered a waiting-list no-treatment arm.Results: The main finding was that participants receiving active treatment showed significant improvements on depression and aphasia severity scores, whereas no significant changes were found in the control group.Conclusions: The implementation of ILAT was efficient in improving clinical language deficits in people with fluent aphasia and contributes to improvement in mood after therapy.Trial registration: EUDRACT (2008-008481-12).

Changes in white matter microstructure related to non-linguistic cognitive impairment in post-stroke aphasia

OBJECTS

Post-stroke aphasia (PSA) often have non-linguistic cognitive impairment. We aimed to ascertain its characteristics of non-linguistic cognitive impairment and the corresponding changes in white matter microstructures.

METHODS

Ten patients with PSA and 17 healthy controls (HCs) were enrolled. Loewenstein occupational therapy cognitive assessment (LOTCA) were used to assess non-linguistic cognitive function. Summary T-test was performed to compare the LOTCA scores between PSA and the Chinese norm. Tract-based spatial statistics (TBSS) was used to calculate fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD) after collecting diffusion tensor imaging data. Correlation analysis was performed between these metrics and LOTCA scores.

RESULTS

The days after stroke onset of PSA was 428.0±52.0. The total LOTCA score of PSA (78.20±22.63) was lower than the Chinese norm (97.65±16.24, P=0.003), as well as the scores of orientation, spatial perception (SP), motor praxis (MP), and attention (P<0.05). Lower FA and higher MD/RD in bilateral inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), and left superior longitudinal fasciculus (SLF) were found in PSA compared with HCs. The MD and RD of the right uncinate fasciculus (UF) was negatively correlated with SP and MP scores (r=-0.787, r=-0.733, r=-0.726; P<0.05). The FA of left UF was negatively correlated with orientation score (r=-0.690, P=0.04).

CONCLUSION

Patients with PSA have non-linguistic cognitive impairment. The integrity of the white matter microstructures can be extensively damaged. Impaired SP and MP in patients with PSA are related to UF damage.

Assessing and mapping language, attention and executive multidimensional deficits in stroke aphasia

There is growing awareness that aphasia following a stroke can include deficits in other cognitive functions and that these are predictive of certain aspects of language function, recovery and rehabilitation. However, data on attentional and executive (dys)functions in individuals with stroke aphasia are still scarce and the relationship to underlying lesions is rarely explored. Accordingly in this investigation, an extensive selection of standardized non-verbal neuropsychological tests was administered to 38 individuals with chronic post-stroke aphasia, in addition to detailed language testing and MRI. To establish the core components underlying the variable patients’ performance, behavioural data were explored with rotated principal component analyses, first separately for the non-verbal and language tests, then in a combined analysis including all tests. Three orthogonal components for the non-verbal tests were extracted, which were interpreted as shift-update, inhibit-generate and speed. Three components were also extracted for the language tests, representing phonology, semantics and speech quanta. Individual continuous scores on each component were then included in a voxel-based correlational methodology analysis, yielding significant clusters for all components. The shift-update component was associated with a posterior left temporo-occipital and bilateral medial parietal cluster, the inhibit-generate component was mainly associated with left frontal and bilateral medial frontal regions, and the speed component with several small right-sided fronto-parieto-occipital clusters. Two complementary multivariate brain-behaviour mapping methods were also used, which showed converging results. Together the results suggest that a range of brain regions are involved in attention and executive functioning, and that these non-language domains play a role in the abilities of patients with chronic aphasia. In conclusion, our findings confirm and extend our understanding of the multidimensionality of stroke aphasia, emphasize the importance of assessing non-verbal cognition in this patient group and provide directions for future research and clinical practice. We also briefly compare and discuss univariate and multivariate methods for brain-behaviour mapping.

The Domain-General Multiple Demand (MD) Network Does Not Support Core Aspects of Language Comprehension: A Large-Scale fMRI Investigation

Aside from the language-selective left-lateralized frontotemporal network, language comprehension sometimes recruits a domain-general bilateral frontoparietal network implicated in executive functions: the multiple demand (MD) network. However, the nature of the MD network's contributions to language comprehension remains debated. To illuminate the role of this network in language processing in humans, we conducted a large-scale fMRI investigation using data from 30 diverse word and sentence comprehension experiments (481 unique participants [female and male], 678 scanning sessions). In line with prior findings, the MD network was active during many language tasks. Moreover, similar to the language-selective network, which is robustly lateralized to the left hemisphere, these responses were stronger in the left-hemisphere MD regions. However, in contrast with the language-selective network, the MD network responded more strongly (1) to lists of unconnected words than to sentences, and (2) in paradigms with an explicit task compared with passive comprehension paradigms. Indeed, many passive comprehension tasks failed to elicit a response above the fixation baseline in the MD network, in contrast to strong responses in the language-selective network. Together, these results argue against a role for the MD network in core aspects of sentence comprehension, such as inhibiting irrelevant meanings or parses, keeping intermediate representations active in working memory, or predicting upcoming words or structures. These results align with recent evidence of relatively poor tracking of the linguistic signal by the MD regions during naturalistic comprehension, and instead suggest that the MD network's engagement during language processing reflects effort associated with extraneous task demands.SIGNIFICANCE STATEMENT Domain-general executive processes, such as working memory and cognitive control, have long been implicated in language comprehension, including in neuroimaging studies that have reported activation in domain-general multiple demand (MD) regions for linguistic manipulations. However, much prior evidence has come from paradigms where language interpretation is accompanied by extraneous tasks. Using a large fMRI dataset (30 experiments/481 participants/678 sessions), we demonstrate that MD regions are engaged during language comprehension in the presence of task demands, but not during passive reading/listening, conditions that strongly activate the frontotemporal language network. These results present a fundamental challenge to proposals whereby linguistic computations, such as inhibiting irrelevant meanings, keeping representations active in working memory, or predicting upcoming elements, draw on domain-general executive resources.

Reliability of BOLD signals in chronic stroke-induced aphasia

Investigating the neurobiology of language impairment and treatment in chronic stroke aphasia using fMRI requires an understanding of measurement variability within and between participants. In this multicenter study, we evaluated the scan-rescan reliability of an auditory and visual (written) story comprehension paradigm in stroke participants with aphasia (N = 65) and healthy controls (N = 22). The multi-modal task was conducted twice (~1 week apart) on separate visits upon study enrolment and twice again at completion three months later. A non-language visuomotor task was studied in the aphasia group only, which was conducted once per time point (3 months apart). While participants were asked to make responses during the comprehension task, these in-scanner responses were not recorded. Reliability was assessed using intraclass correlation coefficient (ICC) at both group and individual participant levels. The visual story comprehension condition had higher reliability than the auditory condition in both groups, with participants with aphasia exhibiting lower reliability than controls in both conditions (stroke ICC = .43, healthy ICC = .81). Differences in reliability within the group of participants with aphasia were found to be partially explained by overall language impairment as well as greater head motion. In the participants with aphasia, the visuomotor paradigm was found to have greater reliability than the story comprehension task at equivalent interscan intervals (visuomotor = 0.50, comprehension = 0.34), and its reliability was not associated with language impairment. This work highlights the importance of considering the reliability of fMRI tasks in aphasia research, provides strategies to improve reliability and has potential implications for the field of clinical neuroimaging in general.

Executive control in frontal lesion aphasia: Does verbal load matter?

Executive control impairments in aphasia resulting from frontal lesions are expected, given that integrity of frontal regions is critical to executive control task performance. Yet the consistency of executive control impairments in aphasia is poorly understood. This is due to previous studies using only a brief set of measures or failing to account for the high language processing demands of many executive control tasks. This study investigated performance across a series of specific and broad executive control task, whilst comparing differences between low or high verbal task versions. Ten participants with aphasia secondary to left inferior frontal lesions and fifteen age matched controls completed a battery of verbal and low verbal executive control tasks tapping into the three core domains of inhibiting, switching, and updating of working memory. For both controls and participants with aphasia, there was no consistent influence of verbal load on either reaction time or accuracy performance. When compared to controls, participants with aphasia demonstrate a general slowing of responses across all reaction time tasks, and are less accurate on switching and updating tasks. These findings do suggest that language processing is not essential for executive control task performance, given that verbal load does not matter. Furthermore, tasks which involve holding multiple sources of information in mind, such as during switching or updating, are particularly vulnerable in aphasia.

Nonlinguistic Cognitive Factors Predict Treatment-Induced Recovery in Chronic Poststroke Aphasia

OBJECTIVE

To determine if pretreatment nonlinguistic cognition predicted language treatment outcomes and if so, which specific nonlinguistic cognitive subskills predicted naming therapy outcomes.

DESIGN

Retrospective.

SETTING

Research clinic.

PARTICIPANTS

Study 1 included data from 67 persons with aphasia who underwent language treatment and a pretreatment cognitive-linguistic assessment battery (N=67). Study 2 included data from 27 study 1 participants who completed additional pretreatment nonlinguistic cognitive assessments.

INTERVENTIONS

120-minute sessions of sentence comprehension (n=26) or naming treatment (n=41) 2 times per week for up to 10-12 weeks.

MAIN OUTCOME MEASURES

Proportion of potential maximal gain (PMG) (assessed immediately after treatment [10-12wk]; formula=mean posttreatment score-mean pretreatment score/total number of trained items-mean pretreatment score) and proportion of potential maximal gain maintained (PMGM) (assessed 12wk after posttreatment [22-24wk]; formula=mean maintenance score-mean pretreatment score/total number of trained items-mean pretreatment score) as outcome variables; and pretreatment assessment scores as predictor variables.

RESULTS

In study 1, 37% of participants demonstrated nonlinguistic cognitive deficits. Principal component analyses reduced assessment data to 2 components: linguistic and nonlinguistic cognition. Backward elimination regression revealed that higher linguistic and nonlinguistic cognitive function significantly predicted higher PMG after language therapy. In study 2, principal component analysis of only the nonlinguistic cognitive measures identified 3 components: executive function, verbal short-term memory, and visual short-term memory. Controlling for pretreatment apraxia of speech and auditory comprehension deficits, regression analyses revealed that higher executive function and visual short-term memory significantly predicted higher PMG and PMGM after naming therapy.

CONCLUSIONS

Pretreatment nonlinguistic cognitive function significantly influenced language treatment outcomes and maintenance of therapy gains.

The role of executive control in post-stroke aphasia treatment

Executive control (EC) ability is increasingly emerging as an important predictor of post-stroke aphasia recovery. This study examined whether EC predicted immediate treatment gains, treatment maintenance and generalization after naming therapy in ten adults with mild to severe chronic post-stroke aphasia. Performance on multiple EC tasks allowed for the creation of composite scores for common EC, and the EC processes of shifting, inhibition and working memory (WM) updating. Participants were treated three times a week for five weeks with a phonological naming therapy; difference scores in naming accuracy of treated and untreated words (assessed pre, post, four- and eight-weeks after therapy) served as the primary outcome measures. Results from simple and multiple linear regressions indicate that individuals with better shifting and WM updating abilities demonstrated better maintenance of treated words at four-week follow-up, and those with better common EC demonstrated better maintenance of treated words at both four- and eight-week follow-ups. Better shifting ability also predicted better generalization to untreated words post-therapy. Measures of EC were not indicative of improvements on treated words immediately post-treatment, nor of generalization to untreated words at follow-up. Findings suggest that immediate treatment gains, maintenance and generalization may be supported by different underlying mechanisms.

Responsiveness, Minimal Clinically Important Difference, and Validity of the MoCA in Stroke Rehabilitation

Objective

Persons with stroke frequently suffer from cognitive impairment. The Montreal Cognitive Assessment (MoCA), a recently developed screening tool, is sensitive to poststroke cognitive deficits. The present study assessed its psychometric and clinimetric properties (i.e., responsiveness, minimal clinically important difference (MCID), and criterion validity) in stroke survivors receiving rehabilitative therapy.

Method

The MoCA and the Stroke Impact Scale (SIS) were administered to 65 stroke survivors before and after 4 to 5 weeks of therapy. The effect size and standardized response mean (SRM) were calculated for responsiveness. Anchor- and distribution-based methods were used to estimate the MCID. Criterion validity was measured with the Spearman correlation coefficient.

Results

The responsiveness of the MoCA was moderate (SRM = 0.67). Participants exceeding the MCID according to the anchor- and distribution-based approaches were 33 (50.77%) and 20 (30.77%), respectively. Fair to good concurrent validity was reported between the MoCA and the SIS communication subscale. The MoCA had satisfactory predictive validity with the SIS communication and memory subscales.

Conclusion

This study may support the responsiveness, MCID, and criterion validity of the MoCA in stroke populations. Future studies with larger sample sizes are needed to validate the current findings.

Development and Validation of Neuro-Cognitive Assessment Battery for Stroke Patients (NCABS) in Pakistan

Background & Objective:

Post Stroke Cognitive Impairments (PSCI) occur frequently in stroke survivors resulting in devastating consequences affecting daily living of survivors. Currently, there exists scarcity of sound assessment tools for the evaluation of PSCI as most of the commonly used scales offer a number of clinical (requires motor and linguistic skills) and cultural limitations (requires academic exposure). Therefore, current study was aimed at evaluating the efficacy of Neuro-Cognitive Assessment Battery for Stroke patients (N-CABS) in Pakistan.

Methods:

The participants were randomized in two groups including clinical and non-clinical group. N-CABS was administered on 61 clinical and 60 non-clinical participants (mean age=45 years; SD=5.55). Both groups were matched on all demographic variables including; age, gender, education and occupation. The psychometric properties of N-CABS were established through a number of robust measures of validity (construct, concurrent and discriminant validity) and reliability (internal consistency and test retest reliability).

Results:

The factor analysis suggested a two-factor solution (labeled as Verbal Cognitive Abilities and Visual Cognitive Abilities) for N-CABS explaining 67% of total variance. A significant test-retest reliability was found (α = 0.92, ^***p<0.001). The findings of concurrent validity recommended a significant correlation between N-CABS and Montreal Cognitive Assessment (MoCA) (α = 0.82, ^***p<0.001). Similarly, discriminant validity also revealed significant group differences to exist on N-CABS (^***p<0.001) suggesting N-CABS be able to discriminate between patients and healthy controls.

Conclusion:

The results of the current study favor N-CABS as a psychometrically strong screening instrument to screen PSCI in our culture.

Development and Standardization of a New Cognitive Assessment Test Battery for Chinese Aphasic Patients: A Preliminary Study

Background:

Nonlinguistic cognitive impairment has become an important issue for aphasic patients, but currently there are few neuropsychological cognitive assessment tests for it. To get more information on cognitive impairment of aphasic patients, this study aimed to develop a new cognitive assessment test battery for aphasic patients, the Non-language-based Cognitive Assessment (NLCA), and evaluate its utility in Chinese-speaking patients with aphasia.

Methods:

The NLCA consists of five nonverbal tests, which could assess five nonlinguistic cognitive domains such as visuospatial functions, attention test, memory, reasoning, and executive functions of aphasic patients. All tests are modified from the nonverbal items of the current existed tests with some changes to the characteristics of Chinese culture. The NLCA was tested in 157 participants (including 57 aphasic patients, 50 mild cognitive impairment (MCI) patients, and 50 normal controls), and was compared with other well-established relative neuropsychological tests on the reliability, validity, and utility.

Results:

The NLCA was fully applicable in the MCI patients and the normal controls, almost working in the aphasic patients (57/62 patients, 91.9%). The NLCA scores were 66.70 ± 6.30, 48.67 ± 15.04, and 77.58 ± 2.56 for the MCI group, the aphasic group, and the control group, respectively, and a significant difference was found among three groups (F = 118.446, P < 0.001). The Cronbach's alpha of the NLCA as an index of internal consistency was 0.805, and the test-retest and interrater reliability was adequate (r=0.977 and r= 0.970, respectively). The correlations of the cognitive subtests and their validation instruments were between 0.540 and 0.670 (all P < 0.05). Spearman's correlation analysis indicated that the coefficient of internal consistency of each subtest itself was higher than other subtests. When choosing the Montreal Cognitive Assessment score of <26 as the diagnostic criteria of cognitive impairment, the area under the curve for all participants in the control and MCI groups was 0.942 (95% confidence interval: 0.895–0.989), and an optimal cutoff point of 75.00 seemed to provide the best balance between sensitivity and specificity. Age (r = −0.406, P < 0.001) was the main influence factor for the NLCA.

Conclusions:

The NLCA could efficiently differentiate the cognitive impairment patients from the normal controls and is a reliable and valid cognitive assessment test battery to specially find nonlinguistic cognitive function for aphasic patients.

Cognitive functioning in chronic post-stroke aphasia

There is a minimal amount of knowledge regarding the cognitive abilities of people with aphasia. We evaluated the performance of individuals with chronic aphasia (AP) and control participants without aphasia (CP) with left hemisphere stroke in a battery of nonverbal cognitive tests and its relationship with aphasia severity, comprehension abilities, and speech fluency in a prospective cross-sectional study. Cognitive evaluation comprised 10 nonverbal tests. Scores were converted to age and education adjusted standard scores. Forty-eight AP and 32 CP were included. AP average scores were below normal range in three tests: Camel and Cactus Test, immediate recall of 5 Objects Test and Spatial Span. The mean test scores were significantly lower in AP than in CP, except in four tests. Aphasia severity and verbal comprehension ability correlated significantly with semantic memory, constructive abilities and attention/processing speed tests. Subjects with nonfluent aphasia had lower scores than CP in memory, executive functions and attention tests, while subjects with fluent aphasia showed lower scores in memory tests only. On average half of the individuals with aphasia exhibit results within the normal range. Nonetheless, their performance was worse than that of controls, despite the fact that many tests do not correlate with the severity of language disorder.

Aerobic Exercise as an Adjuvant to Aphasia Therapy: Theory, Preliminary Findings, and Future Directions

PURPOSE

This study investigated whether participation in aerobic exercise enhances the effects of aphasia therapy, and the degree to which basal serum brain-derived neurotropic factor (BDNF) concentrations fluctuate after the beginning of aerobic exercise or stretching activities in individuals with poststroke aphasia.

METHODS

The study used a single-subject, multiple-baseline design. Seven individuals with chronic poststroke aphasia participated in 2 Blocks of aphasia therapy: aphasia therapy alone (Block 1), followed by aphasia therapy with the addition of aerobic activity via bicycle ergometer (n = 5) or stretching (n = 2) (Block 2). Serum BDNF concentrations from blood draws were analyzed in 4 participants who exercised and in 1 participant who stretched.

FINDINGS

Three of the five exercise participants demonstrated larger Tau-U effects when aphasia therapy was paired with aerobic exercise, whereas 1 of the 2 stretching participants demonstrated a larger effect size when aphasia therapy was paired with stretching. Group-level comparisons revealed a greater overall increase in effect size in the aerobic exercise group, as indicated by differences in Tau-U weighted means. BDNF data showed that all 4 exercise participants demonstrated a decrease in BDNF concentrations during the first 6 weeks of exercise and an increase in BDNF levels near or at baseline during the last 6 weeks of exercise. The stretching participant did not show the same pattern.

IMPLICATIONS

Additional research is needed to understand the mechanism of effect and to identify the factors that mediate response to exercise interventions, specifically the optimal dose of exercise and timing of language intervention with exercise. ClinicalTrials.gov identifier: NCT01113879.

Neuropsychological assessment of 86-year-old man with Broca's aphasia complaining of memory difficulties

We report the clinical assessment of J.P., an 86 year-old man with Broca's aphasia complaining of memory problems. Our aim was to objectively investigate his level of cognitive functioning using standardized neuropsychological tests in order to determine the nature of his memory impairment. J.P.'s medical history included left-middle cerebral artery (left-MCA) stroke, high frequency hearing loss, macular degeneration, and a recent hospitalization related to a fall. Results from his neuropsychological testing and from information gathered during the clinical interview with his wife suggested that a deficit in executive functioning might have been the source for some of his perceived memory problems. We were unable to detect any progressive cognitive decline that might have been suggestive of something more sinister. Despite his age J.P. was a fully functioning and highly contributing member of his society who was completing quite complex activities of daily living (ADLs). We provided J.P. with a compensatory set of strategies in order for him to circumvent his executive difficulties and impairment in expressive language. In the elderly population survivors of stroke are continuing to rise with improvements in drug treatment and primary care. This case study is important as it provides information on neuropsychological assessment in aphasia; and draws attention to valuable information in a client's clinical history that might help clarify the prognosis.

Different Cognitive Profiles of Patients with Severe Aphasia

Cognitive dysfunction frequently occurs in aphasic patients and primarily compromises linguistic skills. However, patients suffering from severe aphasia show heterogeneous performance in basic cognition. Our aim was to characterize the cognitive profiles of patients with severe aphasia and to determine whether they also differ as to residual linguistic abilities. We examined 189 patients with severe aphasia with standard language tests and with the CoBaGA (Cognitive Test Battery for Global Aphasia), a battery of nonverbal tests that assesses a wide range of cognitive domains such as attention, executive functions, intelligence, memory, visual-auditory recognition, and visual-spatial abilities. Twenty patients were also followed longitudinally in order to assess their improvement in cognitive skills after speech therapy. Three different subgroups of patients with different types and severity of cognitive impairment were evidenced. Subgroups differed as to residual linguistic skills, in particular comprehension and reading-writing abilities. Attention, reasoning, and executive functions improved after language rehabilitation. This study highlights the importance of an extensive evaluation of cognitive functions in patients with severe aphasia.

Determining the Association between Language and Cognitive Tests in Poststroke Aphasia

BACKGROUND

Individuals with aphasia are often excluded from studies exploring poststroke cognition because so many of the standard cognitive assessments rely on language ability. Our primary objective was to examine the association between performance on cognitive tests and performance on comprehension and naming tests in poststroke aphasia. Second, we aimed to determine the association between language performance and a real-life measure of cognition (Kettle Test). Third, we explored the feasibility of administering cognitive tests in aphasia.

METHODS

Thirty-six participants with poststroke aphasia and 32 controls were assessed on a battery of pen-and-paper cognitive tests recommended in stroke. Auditory comprehension was measured using the Comprehensive Aphasia Test and naming was measured using the Boston Naming Test. Twenty-two community dwelling participants with aphasia and controls were also asked to complete the Kettle Test. Multiple linear regressions were used to explore the relationship between language performance and performance on the cognitive tests. Feasibility was determined by quantifying missing data.

RESULTS

The cognitive tests with the highest variance accounted for by auditory comprehension and naming were animal fluency (R2 = 0.67, R2 = 0.78) and the Hopkins Verbal Learning Test (recognition discrimination index) (R2 = 0.65, R2 = 0.78). All cognitive tests were significantly associated with auditory comprehension and naming, except for the Star Cancellation Test and the Kettle Test. Thirty-three percent of participants with aphasia were unable to complete all the cognitive tests.

CONCLUSION

Language and non-linguistic cognitive processes are often interrelated. Most pen-and-paper cognitive tests were significantly associated with both auditory comprehension and naming, even in tests that do not require a verbal response. Language performance was not significantly associated with a real-life cognitive performance measure. Task instructions, stimuli, and responses for completion need to be tailored for individuals with aphasia to minimize the influence of language deficits when testing non-linguistic cognitive performance.

Influence of Cognitive Ability on Therapy Outcomes for Anomia in Adults With Chronic Poststroke Aphasia

PURPOSE

The relationship between cognitive abilities and aphasia rehabilitation outcomes is complex and remains poorly understood. This study investigated the influence of language and cognitive abilities on anomia therapy outcomes in adults with aphasia.

METHOD

Thirty-four adults with chronic aphasia participated in Aphasia Language Impairment and Functioning Therapy. A language and cognitive assessment battery, including 3 baseline naming probes, was administered prior to therapy. Naming accuracy for 30 treated and 30 untreated items was collected at posttherapy and 1-month follow-up. Multiple regression models were computed to evaluate the relationship between language and cognitive abilities at baseline and anomia therapy outcomes.

RESULTS

Both language and cognitive variables significantly influenced anomia therapy gains. Verbal short-term memory ability significantly predicted naming gains for treated items at posttherapy (β = -.551, p = .002) and for untreated items at posttherapy (β = .456, p = .014) and 1-month follow-up (β = .455, p = .021). Furthermore, lexical-semantic processing significantly predicted naming gains for treated items at posttherapy (β = -.496, p = .004) and 1-month follow-up (β = .545, p = .012).

CONCLUSIONS

Our findings suggest that individuals' cognitive ability, specifically verbal short-term memory, affects anomia treatment success. Further research into the relationship between cognitive ability and anomia therapy outcomes may help to optimize treatment techniques.

Relationship between Self-Administered Cues and Rehabilitation Outcomes in Individuals with Aphasia: Understanding Individual Responsiveness to a Technology-Based Rehabilitation Program

An advantage of rehabilitation administered on computers or tablets is that the tasks can be self-administered and the cueing required to complete the tasks can be monitored. Though there are many types of cueing, few studies have examined how participants' response to rehabilitation is influenced by self-administered cueing, which is cueing that is always available but the individual decides when and which cue to administer. In this study, participants received a tablet-based rehabilitation where the tasks were selfpaced and remotely monitored by a clinician. The results of the effectiveness of this study were published previously (Des Roches et al., 2015). The current study looks at the effect of cues on accuracy and rehabilitation outcomes. Fifty-one individuals with aphasia completed a 10-week program using Constant Therapy on an iPad targeted at improving language and cognitive deficits. Three questions were examined. The first examined the effect of cues on accuracy collapsed across time. Results showed a trend where the greater the cue use, the lower the accuracy, although some participants showed the opposite effect. This analysis divided participants into profiles based on cue use and accuracy. The second question examined how each profile differed in percent cue use and on standardized measures at baseline. Results showed that the four profiles were significantly different in frequency of cues and scores on WAB-R, CLQT, BNT, and ASHA-FACS, indicating that participants with lower scores on the standardized tests used a higher percentage of cues, which were not beneficial, while participants with higher scores on the standardized tests used a lower frequency of cues, which were beneficial. The third question examined how the relationship between cues and accuracy was affected by the course of treatment. Results showed that both more and less severe participants showed a decrease in cue use and an increase in accuracy over time, though more severe participants continued to used a greater number of cues. It is possible that self-administered cues help some individuals to access information that is otherwise inaccessible, even if there is not an immediate effect. Ultimately, the results demonstrate the need for individually modifying the levels of assistance during rehabilitation. time, though more severe participants continued to used a greater number of cues. It is possible that self-administered cues help some individuals to access information that is otherwise inaccessible, even if there is not an immediate effect. Ultimately, the results demonstrate the need for individually modifying the levels of assistance during rehabilitation.