Treatment-induced neural reorganization in aphasia is language-domain specific: Evidence from a large-scale fMRI study.

Studies investigating the effects of language intervention on the re-organization of language networks in chronic aphasia have resulted in mixed findings, likely related to-among other factors-the language function targeted during treatment. The present study investigated the effects of the type of treatment provided on neural reorganization. Seventy individuals with chronic stroke-induced aphasia, recruited from three research laboratories and meeting criteria for agrammatism, anomia or dysgraphia were assigned to either treatment (N = 51) or control (N = 19) groups.

Structural disconnections associated with language impairments in chronic post-stroke aphasia using disconnectome maps.

Inconsistent findings have been reported about the impact of structural disconnections on language function in post-stroke aphasia. This study investigated patterns of structural disconnections associated with chronic language impairments using disconnectome maps. Seventy-six individuals with post-stroke aphasia underwent a battery of language assessments and a structural MRI scan.

The Role of Working Memory, Short-Term Memory, Speed of Processing, Education, and Locality in Verb-Related Morphosyntactic Production: Evidence From Greek.

This study investigates the relationship between verb-related morphosyntactic production (VRMP) and locality (i.e., critical cue being adjacent to the target or not), verbal Working Memory (vWM), nonverbal/visuospatial WM (nvWM), verbal short-term memory (vSTM), nonverbal/visuospatial STM (nvSTM), speed of processing, and education.

Perilesional Perfusion in Chronic Stroke-Induced Aphasia and Its Response to Behavioral Treatment Interventions.

Stroke-induced alterations in cerebral blood flow (perfusion) may contribute to functional language impairments in chronic aphasia, particularly in perilesional tissue. Abnormal perfusion in this region may also serve as a biomarker for predicting functional improvements with behavioral treatment interventions. Using pseudo-continuous arterial spin labeling in magnetic resonance imaging (MRI), we examined perfusion in chronic aphasia, in perilesional rings in the left hemisphere and their right hemisphere homologues.

Multimodal Neural and Behavioral Data Predict Response to Rehabilitation in Chronic Poststroke Aphasia.

Background: Poststroke recovery depends on multiple factors and varies greatly across individuals. Using machine learning models, this study investigated the independent and complementary prognostic role of different patient-related factors in predicting response to language rehabilitation after a stroke.

Methods: Fifty-five individuals with chronic poststroke aphasia underwent a battery of standardized assessments and structural and functional magnetic resonance imaging scans, and received 12 weeks of language treatment.

A Computational Evaluation of Two Models of Retrieval Processes in Sentence Processing in Aphasia.

Can sentence comprehension impairments in aphasia be explained by difficulties arising from dependency completion processes in parsing? Two distinct models of dependency completion difficulty are investigated, the Lewis and Vasishth (2005) activation-based model and the direct-access model (DA; McElree, 2000). These models' predictive performance is compared using data from individuals with aphasia (IWAs) and control participants. The data are from a self-paced listening task involving subject and object relative clauses.

Predicting language recovery in post-stroke aphasia using behavior and functional MRI.

Language outcomes after speech and language therapy in post-stroke aphasia are challenging to predict. This study examines behavioral language measures and resting state fMRI (rsfMRI) as predictors of treatment outcome. Fifty-seven patients with chronic aphasia were recruited and treated for one of three aphasia impairments: anomia, agrammatism, or dysgraphia.

Cautionary notes on diagnosing functional neurologic disorder as a neurologist-in-training.

Functional neurologic disorder (FND), although neglected for much of the 20th century, is among the most common conditions encountered by neurologists across clinical settings. High prevalence rates and limited provider expertise in FND have created a considerable need to develop educational initiatives and practical suggestions to guide neurologists in training working with this population. To help avoid diagnostic errors, trainees should keep in mind that (1) marginally positive functional examination signs have low specificity; (2) FND can coexist with other neurologic comorbidities; and (3) bizarre, not previously encountered, neurologic presentations should not be mistakenly diagnosed as FND.

Common and distinct neural substrates of sentence production and comprehension.

Functional neuroimaging and lesion-symptom mapping investigations implicate a left frontal-temporal-parietal network for sentence processing. The majority of studies have focused on sentence comprehension, with fewer in the domain of sentence production, which have not fully elucidated overlapping and/or unique brain structures associated with the two domains, particularly for sentences with noncanonical word order. Using voxel-based lesion symptom mapping (VLSM) we examined the relationship between lesions within the left hemisphere language network and both sentence comprehension and production of simple and complex syntactic structures in 76 participants with chronic stroke-induced aphasia.

White Matter Hyperintensities Predict Response to Language Treatment in Poststroke Aphasia.

Background: White matter hyperintensities (WMH) are a radiological marker of brain health that has been associated with language status in poststroke aphasia; however, its association with language treatment outcomes remains unknown.

Objective: To determine whether WMH in the right hemisphere (RH) predict response to language therapy independently from demographics and stroke lesion-related factors in poststroke aphasia.

Methods: We used the Fazekas scale to rate WMH in the RH in 30 patients with poststroke aphasia who received language treatment.

Telemedicine in Behavioral Neurology-Neuropsychiatry: Opportunities and Challenges Catalyzed by COVID-19.

Coronavirus 2019 (COVID-19) has profoundly impacted the well-being of society and the practice of medicine across health care systems worldwide. As with many other subspecialties, the clinical paradigm in behavioral neurology and neuropsychiatry (BN-NP) was transformed abruptly, transitioning to real-time telemedicine for the assessment and management of the vast majorities of patient populations served by our subspecialty. In this commentary, we outline themes from the BN-NP perspective that reflect the emerging lessons we learned using telemedicine during the COVID-19 pandemic.

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.

Pain Catastrophizing and Limiting Behavior Mediate the Association Between Anxiety and Postconcussion Symptoms.

Background: Despite growing evidence that anxiety is critical in the development and maintenance of postconcussion symptoms after mild traumatic brain injury (mTBI), little is known about potential mechanisms through which anxiety may affect these symptoms.

Objective: To test the strength and reliability of cognitive (pain catastrophizing) and behavioral (limiting behaviors) pathways mediating the relationship between anxiety and postconcussion symptoms among patients with mTBI.

Method: Patients with mTBI (N = 57) completed self-report measures of anxiety, postconcussion symptoms, pain catastrophizing, and limiting behavior.

Comparison of Measures to Predict Mortality and Length of Stay in Hospitalized Patients.

Background: Patient risk adjustment is critical for hospital benchmarking and allocation of healthcare resources. However, considerable heterogeneity exists among measures.

Objectives: The performance of five measures was compared to predict mortality and length of stay (LOS) in hospitalized adults using claims data; these include three comorbidity composite scores (Charlson/Deyo age-comorbidity score, V W Elixhauser comorbidity score, and V W Elixhauser age-comorbidity score), 3 M risk of mortality (3 M ROM), and 3 M severity of illness (3 M SOI) subclasses.

Neural networks for sentence comprehension and production: An ALE-based meta-analysis of neuroimaging studies.

Comprehending and producing sentences is a complex endeavor requiring the coordinated activity of multiple brain regions. We examined three issues related to the brain networks underlying sentence comprehension and production in healthy individuals: First, which regions are recruited for sentence comprehension and sentence production? Second, are there differences for auditory sentence comprehension vs. visual sentence comprehension? Third, which regions are specifically recruited for the comprehension of syntactically complex sentences? Results from activation likelihood estimation (ALE) analyses (from 45 studies) implicated a sentence comprehension network occupying bilateral frontal and temporal lobe regions.

Communication impairment in Parkinson's disease: Impact of motor and cognitive symptoms on speech and language.

Communication impairment is common in Parkinson's disease (PD) and may have both motor speech control and cognitive-linguistic underpinnings. The neurobiology of communication impairment in PD is poorly understood, and work is needed to disentangle the relative contributions of motor and cognitive dysfunction. In clinical practice, cognitive-linguistic impairments are often overlooked despite the large body of research on this topic in neurocognitive and linguistics literature.

Morphosyntactic Production and Verbal Working Memory: Evidence From Greek Aphasia and Healthy Aging.

Purpose: The present work investigated whether verbal working memory (WM) affects morphosyntactic production in configurations that do not involve or favor similarity-based interference and whether WM interacts with verb-related morphosyntactic categories and/or cue-target distance (locality). It also explored whether the findings related to the questions above lend support to a recent account of agrammatic morphosyntactic production: Interpretable Features' Impairment Hypothesis (Fyndanis, Varlokosta, & Tsapkini, 2012).

Method: A sentence completion task testing production of subject-verb agreement, tense/time reference, and aspect in local and nonlocal conditions and two verbal WM tasks were administered to 8 Greek-speaking persons with agrammatic aphasia (PWA) and 103 healthy participants.

A Computational Investigation of Sources of Variability in Sentence Comprehension Difficulty in Aphasia.

We present a computational evaluation of three hypotheses about sources of deficit in sentence comprehension in aphasia: slowed processing, intermittent deficiency, and resource reduction. The ACT-R based Lewis and Vasishth (2005) model is used to implement these three proposals. Slowed processing is implemented as slowed execution time of parse steps; intermittent deficiency as increased random noise in activation of elements in memory; and resource reduction as reduced spreading activation.

Right Hemisphere Grey Matter Volume and Language Functions in Stroke Aphasia.

The role of the right hemisphere (RH) in recovery from aphasia is incompletely understood. The present study quantified RH grey matter (GM) volume in individuals with chronic stroke-induced aphasia and cognitively healthy people using voxel-based morphometry. We compared group differences in GM volume in the entire RH and in RH regions-of-interest.

Neuropsychiatric Associations With Gender, Illness Duration, Work Disability, and Motor Subtype in a U.S. Functional Neurological Disorders Clinic Population.

The assessment of functional neurological disorders (FND) requires an interdisciplinary approach. The authors retrospectively reviewed charts for 100 outpatients with FND and used univariate and regression analyses to investigate neuropsychiatric associations with gender, illness duration, and work disability; secondary analyses evaluated for differences across motor FND subtypes. Men reported higher rates of cognitive complaints and functional weakness, whereas women endorsed increased past physical/sexual trauma.

Intrahemispheric Perfusion in Chronic Stroke-Induced Aphasia.

Stroke-induced alterations in cerebral blood flow (perfusion) may contribute to functional language impairments and recovery in chronic aphasia. Using MRI, we examined perfusion in the right and left hemispheres of 35 aphasic and 16 healthy control participants. Across 76 regions (38 per hemisphere), no significant between-subjects differences were found in the left, whereas blood flow in the right was increased in the aphasic compared to the control participants.

Evaluating Treatment and Generalization Patterns of Two Theoretically Motivated Sentence Comprehension Therapies.

Purpose: The current study examined treatment outcomes and generalization patterns following 2 sentence comprehension therapies: object manipulation (OM) and sentence-to-picture matching (SPM). Findings were interpreted within the framework of specific deficit and resource reduction accounts, which were extended in order to examine the nature of generalization following treatment of sentence comprehension deficits in aphasia.

Method: Forty-eight individuals with aphasia were enrolled in 1 of 8 potential treatment assignments that varied by task (OM, SPM), complexity of trained sentences (complex, simple), and syntactic movement (noun phrase, wh-movement).