Inappropriate trusting behaviour in dementia.

Background: Inappropriate trusting behaviour may have significant social, financial and other consequences for people living with dementia. However, its clinical associations and predictors have not been clarified. Here we addressed this issue in canonical syndromes of frontotemporal dementia (FTD) and Alzheimer's disease (AD). Methods: In 34 patients with AD and 73 with FTD (27 behavioural variant (bv)FTD, 22 semantic variant primary progressive aphasia (svPPA), 24 nonfluent/agrammatic variant (nfv)PPA) we recorded inappropriate trusting and other abnormal socio-emotional behaviours using a semi-structured caregiver survey. Patients were comprehensively characterised using a general cognitive assessment and the Revised Self-Monitoring Scale (RSMS; an informant index of socioemotional awareness). Results: Inappropriate trusting was more frequent in svPPA (55%) and bvFTD (44%) than nfvPPA (17%) or AD (24%). After adjusting for age, sex, education and Mini-Mental State Examination (MMSE) score, inappropriate trusting was significantly more likely in svPPA (odds ratio 3.61; 95% confidence interval 1.41-8.75) and bvFTD (3.01, 1.23-6.65) than AD. Significant predictors of inappropriate trusting comprised apathy in svPPA, disinhibition and altered pain responsiveness in bvFTD, and lower MMSE and RSMS (self-presentation) scores in AD. Conclusion: Dementia syndromes vary in prevalence and predictors of abnormal trusting behaviour, with implications for clinical counselling and safeguarding.

Dynamic aphasia as an early sign of corticobasal degeneration: Clinico-radio-pathological correlation.

A 72-year-old man presented with a 6-month history of decreased voluntary speech. Sparse speech and decreased word fluency were observed. Articulation, naming, comprehension, and repetition were preserved. Agrammatism and paraphasia were not observed. These characteristics matched those reported as dynamic aphasia. Other findings were mild behavioral symptoms, recent memory impairment, and right hemiparkinsonism. The patient's voluntary speech continued to reduce and behavioral symptoms progressed. Brain MRI including voxel-based morphometric analysis showed left-dominant white matter volume reduction in the frontal lobe including those between the left supplementary motor area (SMA)/preSMA and the frontal operculum, likely involving the frontal aslant tract (FAT). The patient became completely mute after two years from disease onset and died of aspiration pneumonia. The neuropathological diagnosis was corticobasal degeneration (CBD). This case suggests that dynamic aphasia may be the initial sign of CBD and that early involvement of left FAT may be responsible for this feature.

"Staying connected": Speech-language pathologists' perspectives on the communication needs of people with primary progressive aphasia and their family members.

PURPOSE: The research objectives were to explore the communication needs pertaining to (a) people with primary progressive aphasia (PwPPA); (b) family members of PwPPA; and (c) the different variants of primary progressive aphasia (PPA), from the perspectives of speech-language pathologists (SLPs). METHOD: This investigation used a qualitatively driven concurrent mixed methods research design. Data collection involved semi-structured interviews and mixed methods questionnaires with 14 SLPs. Qualitative content analysis of interview and questionnaire data was used to identify codes and categories related to the research objectives. Quantitative analysis of questionnaire data involved single item summaries and cross item tabulations. RESULT: Analysis revealed eight categories of communication need pertaining to PwPPA and six pertaining to their family members. Results regarding communication needs according to variant of PPA revealed limited findings. CONCLUSION: SLPs perceived several important areas of communication need for PwPPA and their family members, highlighting key clinical implications for proactive communication care across the continuum of care. Future research can build on the current findings and integrate the perspectives of PwPPA and their family members on this topic, to develop interventions and explore models of service delivery to meet their progressive and complex communication needs.

Voxel-Based Lesion Analysis of Ideomotor Apraxia.

Ideomotor apraxia is a cognitive disorder most often resulting from acquired brain lesions (i.e., strokes or tumors). Neuroimaging and lesion studies have implicated several brain regions in praxis and apraxia, but most studies have described (sub)acute patients. This study aimed to extend previous research by analyzing data from 115 left hemisphere chronic stroke patients using the praxis subtest of the Western Aphasia Battery, which is divided into four action types: facial, upper limb, complex, and instrumental. Lesion-symptom mapping was used to identify brain regions most critically associated with difficulties in each of the four subtests. Complex and instrumental action deficits were associated with left precentral, postcentral, and superior parietal gyri (Brodmann areas 2, 3, 4, 5, and 6), while the facial and upper limb action deficits maps were restricted to left inferior, middle, and medial temporal gyri (Brodmann areas 20, 21, 22, and 48). We discuss ideas about neuroplasticity and cortical reorganization in chronic stroke and how different methodologies can reveal different aspects of lesion and recovery networks in apraxia.

Carers in post-stroke aphasia: a scoping review of interventions and outcomes beyond communication partner training.

PURPOSE: Carers of people with aphasia face unique challenges. Research has demonstrated that these carers have a higher burden of care and more negative stroke-related outcomes in comparison to carers of stroke survivors without aphasia. The aim of this scoping review was to map the range of interventions for carers other than communication partner training and to examine their outcomes. MATERIALS AND METHODS: We conducted a scoping review on this topic. RESULTS: Twenty studies were included. Most studies were case series with four randomised control trials. Both quantitative and qualitative approaches were used. Most studies occurred during the long-term phase of care. Two interventions had only carers as participants. Interventions were comprised of different combinations of intervention components including psychoeducation, skill-building, and support. There was high variability on who led the interventions, the format, and the dose/schedule. Twenty-eight different outcome measures for carers and dyads were used across various domains with overall positive outcomes post-intervention. CONCLUSIONS: This review uncovered a wide range of formats, dosages, and outcome measures in interventions for carers. Encouragingly, the majority of these interventions included psychoeducation, skill-building, and support components. While most studies were case series, there are promising interventions that have the potential to enhance carer wellbeing.

Carer targeted interventions play an important role in reducing carer burden and increasing psychological wellbeing for carers of people with aphasia post-stroke.A tailored intervention for carers of people with aphasia should include components of psychoeducation, skill-building, and support to meet their needs across the continuum of care.Recognising carers as clients has the potential to improve healthcare outcomes for the carer and the person with aphasia.

Baseline multimodal imaging to predict longitudinal clinical decline in atypical Alzheimer's disease.

There are recognized neuroimaging regions of interest in typical Alzheimer's disease which have been used to track disease progression and aid prognostication. However, there is a need for validated baseline imaging markers to predict clinical decline in atypical Alzheimer's Disease. We aimed to address this need by producing models from baseline imaging features using penalized regression and evaluating their predictive performance on various clinical measures. Baseline multimodal imaging data, in combination with clinical testing data at two time points from 46 atypical Alzheimer's Disease patients with a diagnosis of logopenic progressive aphasia (N = 24) or posterior cortical atrophy (N = 22), were used to generate our models. An additional 15 patients (logopenic progressive aphasia = 7, posterior cortical atrophy = 8), whose data were not used in our original analysis, were used to test our models. Patients underwent MRI, FDG-PET and Tau-PET imaging and a full neurologic battery at two time points. The Schaefer functional atlas was used to extract network-based and regional gray matter volume or PET SUVR values from baseline imaging. Penalized regression (Elastic Net) was used to create models to predict scores on testing at Time 2 while controlling for baseline performance, education, age, and sex. In addition, we created models using clinical or Meta Region of Interested (ROI) data to serve as comparisons. We found the degree of baseline involvement on neuroimaging was predictive of future performance on cognitive testing while controlling for the above measures on all three imaging modalities. In many cases, model predictability improved with the addition of network-based neuroimaging data to clinical data. We also found our network-based models performed superiorly to the comparison models comprised of only clinical or a Meta ROI score. Creating predictive models from imaging studies at a baseline time point that are agnostic to clinical diagnosis as we have described could prove invaluable in both the clinical and research setting, particularly in the development and implementation of future disease modifying therapies.

Impact of quality of care on outcomes in survivors of stroke with aphasia: A linked registry and hospital data observational study.

BACKGROUND: The impact of hospital care quality on patient outcomes in post-stroke aphasia remains unclear. We investigated the impact of nationally-endorsed acute stroke treatments on outcomes post-stroke, by aphasia status. METHODS: Patient-level data from the Australian Stroke Clinical Registry (2009-2013) linked to national deaths, hospital emergency presentations and admissions data were used. Aphasia was identified for the index stroke event (ICD-10 diagnosis code R47.0). Impact of receiving an optimal stroke care bundle (stroke unit care, antihypertensive medication at discharge and discharge care plan) and an acute ischemic stroke (AIS) care bundle (stroke unit care, intravenous thrombolysis and aspirin within 48 h of admission) on outcomes were analysed using multivariable regression models with propensity score adjustment. RESULTS: The study included 12,690 patients with a median age of 76, 54 % male, and 26 % with aphasia. Non-receipt of the optimal stroke care bundle was associated with worse survival, compared to optimal care, in people with aphasia (HR: 3.37; 95 % CI 2.10, 5.40; p < 0.05) and without aphasia (HR: 2.10; 95 % CI 1.19, 3.69; p < 0.05). Notably, the dose-response effect on survival was more pronounced in individuals with aphasia. In those who received the AIS care bundle, readmission within 12 months was greater in those without aphasia (vs aphasia, p-value interaction = 0.001), whereas survival was similar (p-value interaction = 0.731). CONCLUSIONS: Survivors of stroke with aphasia who did not receive the optimal stroke care bundle, had worse survival at 12 months post-stroke. Ensuring eligible patients receive the optimal stroke care bundle is crucial for improving their 12-month survival.

Validity and reliability of the Pain Assessment in Impaired Cognition 15 (PAIC15) observation scale in persons with aphasia.

BACKGROUND: The use of self-report pain scales in persons with aphasia can be challenging due to communication and cognitive problems, while for assessing pain self-report pain is considered the gold standard (Harrison RA, Field TS. Post stroke pain: identification, assessment, and therapy. Cerebrovasc Dis. 2015;39(3-4):190-201.). An observational scale may be used as an alternative. This study examines the validity and reliability of the observational Pain Assessment in Impaired Cognition (PAIC15) scale in persons with aphasia. METHODS: Persons with aphasia were observed during rest and transfer by two observers using the PAIC15. The PAIC15 comprises 15 items covering the three domains of facial expressions, body movements, and vocalizations. When able, the participant completed four self-report pain scales after each observation. The observations were repeated within one week. For criterion validity, correlations between the PAIC15 and self-report pain scales were calculated and for construct validity, three hypotheses were tested. Reliability was determined by assessing internal consistency, and intra- and interobserver agreement. RESULTS: PAIC15 observations were obtained for 71 persons (mean age 75.5 years) with aphasia. Fair positive correlations (rest: 0.35-0.50; transfer: 0.38-0.43) were reported between PAIC15 and almost all self-report pain scales. Results show that significantly more pain was observed in persons with aphasia during transfer than during rest. No differences were found for observed pain between persons with aphasia who use pain medication and those without, or persons who have joint diseases compared to those without. Results showed acceptable internal consistency. Intra- and interobserver agreement was high for most PAIC15 items, particularly for the domains body movements and vocalizations during rest and transfer. CONCLUSIONS: Recognition of pain in persons aphasia using the PAIC15 showed mixed yet promising results.

A Lesion-aware Edge-based Graph Neural Network for Predicting Language Ability in Patients with Post-stroke Aphasia.

We propose a lesion-aware graph neural network (LEGNet) to predict language ability from resting-state fMRI (rs-fMRI) connectivity in patients with post-stroke aphasia. Our model integrates three components: an edge-based learning module that encodes functional connectivity between brain regions, a lesion encoding module, and a subgraph learning module that leverages functional similarities for prediction. We use synthetic data derived from the Human Connectome Project (HCP) for hyperparameter tuning and model pretraining. We then evaluate the performance using repeated 10-fold cross-validation on an in-house neuroimaging dataset of post-stroke aphasia. Our results demonstrate that LEGNet outperforms baseline deep learning methods in predicting language ability. LEGNet also exhibits superior generalization ability when tested on a second in-house dataset that was acquired under a slightly different neuroimaging protocol. Taken together, the results of this study highlight the potential of LEGNet in effectively learning the relationships between rs-fMRI connectivity and language ability in a patient cohort with brain lesions for improved post-stroke aphasia evaluation.

Increased risk of depression and associated symptoms in poststroke aphasia.

Poststroke aphasia hinders patients' emotional processing and social adaptation. This study estimated the risks of depression and related symptoms in patients developing or not developing aphasia after various types of stroke. Using data from the US Collaborative Network within the TriNetX Diamond Network, we conducted a retrospective cohort study of adults experiencing their first stroke between 2013 and 2022. Diagnoses were confirmed using corresponding International Classification of Diseases, Tenth Revision, Clinical Modification codes. Patients were stratified by poststroke aphasia status and stroke type, with propensity score matching performed to control for confounders. The primary outcome was depression within one year post-stroke; secondary outcomes included anxiety, fatigue, agitation, emotional impact, and insomnia. Each matched group comprised 12,333 patients. The risk of depression was significantly higher in patients with poststroke aphasia (hazard ratio: 1.728; 95% CI 1.464-2.038; p < 0.001), especially those with post-hemorrhagic-stroke aphasia (hazard ratio: 2.321; 95% CI 1.814-2.970; p < 0.001). Patients with poststroke aphasia also had higher risks of fatigue, agitation, and emotional impact. Anxiety and insomnia risks were higher in those with post-hemorrhagic-stroke aphasia. Poststroke aphasia, particularly post-hemorrhagic-stroke aphasia, may increase the risks of depression and associated symptoms, indicating the need for comprehensive psychiatric assessments.

Metric comparison of connectome-based lesion-symptom mapping in post-stroke aphasia.

Connectome-based lesion-symptom mapping relates behavioural impairments to disruption of structural brain connectivity. Connectome-based lesion-symptom mapping can be based on different approaches (diffusion MRI versus lesion mask), network scales (whole brain versus regions of interest) and measure types (tract-based, parcel-based, or network-based metrics). We evaluated the similarity of different connectome-based lesion-symptom mapping processing choices and identified factors that influence the results using multiverse analysis-the strategy of conducting and displaying the results of all reasonable processing choices. Metrics derived from lesion masks and diffusion-weighted images were tested for association with Boston Naming Test and Token Test performance in a sample of 50 participants with aphasia following left hemispheric stroke. 'Direct' measures were derived from diffusion-weighted images. 'Indirect' measures were derived by overlaying lesion masks on a white matter atlas. Parcel-based connectomes were constructed for the whole brain and regions of interest (14 language-relevant parcels). Numerous tract-based and network-based metrics were calculated. There was a high discrepancy across processing approaches (diffusion-weighted images versus lesion masks), network scales (whole brain versus regions of interest) and metric types. Results indicate weak correlations and different connectome-based lesion-symptom mapping results across the processing choices. Substantial methodological work is needed to validate the various decision points that arise when conducting connectome-based lesion-symptom mapping analyses. Multiverse analysis is a useful strategy for evaluating the similarity across different processing choices in connectome-based lesion-symptom mapping.

EXPRESS: Pure-tone audiometry and dichotic listening in primary progressive aphasia and Alzheimer's disease.

Hearing is multifaceted and the relative contributions of peripheral and central hearing loss are rarely considered together in the context of dementia. Here, we assessed peripheral (as measured with pure-tone audiometry) and central (as measured with dichotic listening) hearing in 19 patients with typical amnestic Alzheimer's disease (tAD), 10 patients with logopenic variant primary progressive aphasia (lvPPA), 11 patients with nonfluent/agrammatic variant PPA (nfvPPA), 15 patients with semantic variant PPA (svPPA), and 28 healthy age-matched individuals. Participants also underwent neuropsychological assessment and magnetic resonance image scanning, allowing us to use voxel-based morphometry to assess associations between hearing scores and grey matter volume. Dichotic listening was impaired in all patient groups relative to healthy controls. In the combined patient (but not healthy control) cohort, dichotic listening scores were significantly correlated with measures of global cognitive functioning and speech-based neuropsychological tasks. Pure-tone audiometry scores were not significantly elevated in any patient group relative to the healthy control group, and no significant correlations were observed between peripheral hearing and neuropsychological task performance in either the combined patient or healthy control cohorts. Neuroanatomically, dichotic listening performance was associated with grey matter volume in a bilateral fronto-temporo-parietal network over the combined patient cohort, but no correlates were identified for pure-tone audiometry. Our findings highlight the importance of speech parsing mechanisms beyond elementary sound detection in driving cognitive test performance, underline the importance of assessing central hearing alongside peripheral hearing in people with dementia, and further delineate the complex auditory profiles of neurodegenerative dementias.

Sentence comprehension deficits in aphasia disorders: A systematic review of mapping therapy.

Patients with aphasia (PWA), particularly those with agrammatic aphasia, experience problems in sentence comprehension. Studies have found that Mapping Therapy (MT) can improve sentence processing in PWA. This paper aims to review the literature on therapeutic studies using MT for the treatment of sentence processing in PWA. All studies on the treatment of sentence comprehension using MT were found by searching Cochrane Library, ISI Web of Knowledge, Google Scholar, Pubmed, and Scopus from 1986 until December 2023, with the combination of these search keywords: 'aphasia, sentence, comprehension, mapping therapy, treatment, rehabilitation'. All studies (single-subject or group design) on the treatment of sentence comprehension using MT in PWA were reviewed. An adaptation of the Cochrane Collaboration's risk of bias (RoB) tool was used to assess the risk of bias (RoB) in the reviewed studies. A total of 14 studies on 81 participants were selected and reviewed. All studies (13 studies) had employed a single-subject design, except for one study that had used a group design. Twelve studies (86%) showed that MT is effective in the remediation of sentence comprehension in PWA. Generalization to untrained sentences similar to the trained structure was also observed in 12 studies (86%). Generalization to untrained structures (usually passive sentences) was limited. In addition, cross-modal improvement in sentence production was observed in 8 studies (57%). This review highlights the need for a more detailed investigation of the effect of MT on cross-modal generalization using elicited production of the sentence types trained during comprehension treatment.

Subcortical Aphasia: An Update.

PURPOSE OF REVIEW: This review aims to rediscuss the leading theories concerning the role of basal ganglia and the thalamus in the genesis of aphasic symptoms in the absence of gross anatomical lesions in cortical language areas as assessed by conventional neuroimaging studies. RECENT FINDINGS: New concepts in language processing and modern neuroimaging techniques have enabled some progress in resolving the impasse between the current dominant theories: (a) direct and specific linguistic processing and (b) subcortical structures as processing relays in domain-general functions. Of particular interest are studies of connectivity based on functional magnetic resonance imaging (MRI) and tractography that highlight the impact of white matter pathway lesions on aphasia development and recovery. Connectivity studies have put into evidence the central role of the arcuate fasciculus (AF), inferior frontal occipital fasciculus (IFOF), and uncinate fasciculus (UF) in the genesis of aphasia. Regarding the thalamus, its involvement in lexical-semantic processing through modulation of the frontal cortex is becoming increasingly apparent.

The Impact of Poststroke Aphasia on Quality of Life: A Comparative Cross-Sectional Study.

OBJECTIVES: The study aimed to analyze the impact of aphasia on quality of life (QoL) in persons with ischemic stroke per radiological severity, compare equally severe but nonaphasic stroke survivors, and analyze the impact of hyperbaric oxygen therapy (HBOT) exposure. Methods: Patients with first-ever middle cerebral artery (MCA) stroke were categorized by radiological severity into high, intermediate, and low Alberta Stroke Program Early CT Score (ASPECTS). The Stroke Aphasia Quality of Life (SAQoL) Scale was used for outcome analysis. Inclusion criteria were age 40-65, 12-16 months after stroke, MCA distribution, first stroke, and ischemic stroke. Exclusion criteria were mixed vessel involvement and concomitant neurological, orthopedic, or psychiatric comorbidities. RESULTS: Among 93 patients with ischemic stroke, 87% presented with intermediate-to-low ASPECTS. According to the SAQoL, locomotion and transfers were the most compromised. QoL was significantly negatively correlated with higher ASPECTS and greater stroke impact in those with aphasia overall (p = 0.001). Those who received HBOT overall were significantly better than those who did not, regardless of group (p = 0.02 and 0.03). CONCLUSION: The present study shows that the radiological severity of stroke relates to QoL in those with poststroke aphasia. Among those with equal radiological severity, those with aphasia are worse off. Those who receive HBOT have better QoL.

AI-assisted assessment and treatment of aphasia: a review.

Aphasia is a language disorder caused by brain injury that often results in difficulties with speech production and comprehension, significantly impacting the affected individuals' lives. Recently, artificial intelligence (AI) has been advancing in medical research. Utilizing machine learning and related technologies, AI develops sophisticated algorithms and predictive models, and can employ tools such as speech recognition and natural language processing to autonomously identify and analyze language deficits in individuals with aphasia. These advancements provide new insights and methods for assessing and treating aphasia. This article explores current AI-supported assessment and treatment approaches for aphasia and highlights key application areas. It aims to uncover how AI can enhance the process of assessment, tailor therapeutic interventions, and track the progress and outcomes of rehabilitation efforts. The article also addresses the current limitations of AI's application in aphasia and discusses prospects for future research.

Aphasia Awareness Among Spiritual Healthcare Providers in the United States.

Spiritual healthcare providers (e.g., chaplains) working in healthcare settings across the United States were surveyed with the goals of (1) understanding their awareness of aphasia (a language disorder affecting reading, writing, verbal communication, and auditory comprehension); (2) determining whether they have received any training in aphasia and what type of training has been received; (3) whether they altered their approach to assessing the spiritual well-being of a person with aphasia; and, (4) what tools were used to augment communication. From a convenience sample of 203 respondents, the results indicated that 96% of respondents had previously heard of aphasia and 85% of respondents correctly identified the definition of aphasia. Seventy-three percent of respondents (N = 128) altered their approach to spiritual well-being assessment due to the aphasia diagnosis. Most respondents did not indicate receiving any formal training related to aphasia.

Establishing Quality Indicators and Implementation Priorities for Post-Stroke Aphasia Services Through End-User Involvement.

BACKGROUND: Currently, there are no agreed quality standards for post-stroke aphasia services. Therefore, it is unknown if care reflects best practices or meets the expectations of people living with aphasia. We aimed to (1) shortlist, (2) operationalise and (3) prioritise best practice recommendations for post-stroke aphasia care. METHODS: Three phases of research were conducted. In Phase 1, recommendations with strong evidence and/or known to be important to people with lived experience of aphasia were identified. People with lived experience and health professionals rated the importance of each recommendation through a two-round e-Delphi exercise. Recommendations were then ranked for importance and feasibility and analysed using a graph theory-based voting system. In Phase 2, shortlisted recommendations from Phase 1 were converted into quality indicators for appraisal and voting in consensus meetings. In Phase 3, priorities for implementation were established by people with lived experience and health professionals following discussion and anonymous voting. FINDINGS: In Phase 1, 23 best practice recommendations were identified and rated by people with lived experience (n = 26) and health professionals (n = 81). Ten recommendations were shortlisted. In Phase 2, people with lived experience (n = 4) and health professionals (n = 17) reached a consensus on 11 quality indicators, relating to assessment (n = 2), information provision (n = 3), communication partner training (n = 3), goal setting (n = 1), person and family-centred care (n = 1) and provision of treatment (n = 1). In Phase 3, people with lived experience (n = 5) and health professionals (n = 7) identified three implementation priorities: assessment of aphasia, provision of aphasia-friendly information and provision of therapy. INTERPRETATION: Our 11 quality indicators and 3 implementation priorities are the first step to enabling systematic, efficient and person-centred measurement and quality improvement in post-stroke aphasia services. Quality indicators will be embedded in routine data collection systems, and strategies will be developed to address implementation priorities. PATIENT AND PUBLIC CONTRIBUTION: Protocol development was informed by our previous research, which explored the perspectives of 23 people living with aphasia about best practice aphasia services. Individuals with lived experience of aphasia participated as expert panel members in our three consensus meetings. We received support from consumer advisory networks associated with the Centre for Research Excellence in Aphasia Rehabilitation and Recovery and the Queensland Aphasia Research Centre.

Embracing virtual reality in rehabilitation of post-stroke aphasia.

About one-third of stroke survivors experience aphasia, i.e., language dysfunction caused by brain damage. Aphasia affects not only a person's ability to communicate, but it often leads to the inability to return to work, loss of close relationships, diminished quality of life, negative self-perception, and depression. Yet persons with aphasia are globally underserved due to limited access to resources, which limits their chance for recovery. Immersive virtual reality (VR) has the potential to solve this problem and deliver efficient, personalized treatments to millions of people worldwide who need access to rehabilitation services or more flexibility in treatment delivery. To reduce the global burden of stroke experts recommend taking bold, pragmatic actions across all four pillars of stroke quadrangle-surveillance, prevention, acute care, and rehabilitation. Embracing immersive VR-based rehabilitation of poststroke aphasia would be one step in that direction.

Prediction models of the aphasia severity after stroke by lesion load of cortical language areas and white matter tracts: An atlas-based study.

OBJECTIVE: To construct relatively objective, atlas-based multivariate models for predicting early aphasia severity after stroke, using structural magnetic resonance imaging. METHODS: We analyzed the clinical and imaging data of 46 patients with post-stroke aphasia. The aphasia severity was identified with a Western Aphasia Battery Aphasia Quotient. The assessments of stroke lesions were indicated by the lesion load of both the cortical language areas (Areas-LL) and four white matter tracts (i.e., the superior longitudinal fasciculus, SLF-LL; the inferior frontal occipital fasciculi, IFOF-LL; the inferior longitudinal, ILF-LL; and the uncinate fasciculi, UF-LL) extracted from human brain atlas. Correlation analyses and multiple linear regression analyses were conducted to evaluate the correlations between demographic, stroke- and lesion-related variables and aphasia severity. The predictive models were then established according to the identified significant variables. Finally, the receiver operating characteristic (ROC) curve was utilized to assess the accuracy of the predictive models. RESULTS: The variables including Areas-LL, the SLF-LL, and the IFOF-LL were significantly negatively associated with aphasia severity (p < 0.05). In multiple linear regression analyses, these variables accounted for 59.4 % of the variance (p < 0.05). The ROC curve analyses yielded the validated area under the curve (AUC) 0.84 both for Areas-LL and SLF-LL and 0.76 for IFOF-LL, indicating good predictive performance (p < 0.01). Adding the combination of SLF-LL and IFOF-LL to this model increased the explained variance to 62.6 % and the AUC to 0.92. CONCLUSIONS: The application of atlas-based multimodal lesion assessment may help predict the aphasia severity after stroke, which needs to be further validated and generalized for the prediction of more outcome measures in populations with various brain injuries.