Severe acute respiratory syndrome coronavirus 2 is the virus resulting in COVID-19 infections in nearly 4.3 million Americans with COVID-19 in the United States as of July 29, 2020, with nearly 150,000 deaths and hundreds of thousands of survivors (https://www.coronavirus.jhu.edu/map.html). This tutorial reviews (a) what has been reported about neurological insults in cases of COVID-19 infection, (b) what is known from similar conditions in other disorders, and (c) how that combined information can inform clinical decision making.
Purpose Brain imaging has provided puzzle pieces in the understanding of language. In neurologically healthy populations, the structure of certain brain regions is associated with particular language functions (e.g., semantics, phonology). In studies on focal brain damage, certain brain regions or connections are considered sufficient or necessary for a given language function. However, few of these account for the effects of lesioned tissue on the “functional” dynamics of the brain for language processing. Here, functional connectivity (FC) among semantic–phonological regions of interest (ROIs) is assessed to fill a gap in our understanding about the neural substrates of impaired language and whether connectivity strength can predict language performance on a clinical tool in individuals with aphasia.
Method Clinical assessment of language, using the Western Aphasia Battery–Revised, and resting-state functional magnetic resonance imaging data were obtained for 30 individuals with chronic aphasia secondary to left-hemisphere stroke and 18 age-matched healthy controls. FC between bilateral ROIs was contrasted by group and used to predict Western Aphasia Battery–Revised scores.
Results Network coherence was observed in healthy controls and participants with stroke. The left–right premotor cortex connection was stronger in healthy controls, as reported by New et al. (2015) in the same data set. FC of (a) connections between temporal regions, in the left hemisphere and bilaterally, predicted lexical–semantic processing for auditory comprehension and (b) ipsilateral connections between temporal and frontal regions in both hemispheres predicted access to semantic–phonological representations and processing for verbal production.
Conclusions Network connectivity of brain regions associated with semantic–phonological processing is predictive of language performance in poststroke aphasia. The most predictive connections involved right-hemisphere ROIs—particularly those for which structural adaptions are known to associate with recovered word retrieval performance. Predictions may be made, based on these findings, about which connections have potential as targets for neuroplastic functional changes with intervention in aphasia.
Purpose The heterogeneous nature of measures, methods, and analyses reported in the aphasia spoken discourse literature precludes comparison of outcomes across studies (e.g., meta-analyses) and inhibits replication. Furthermore, funding and time constraints significantly hinder collecting test–retest data on spoken discourse outcomes. This research note describes the development and structure of a working group, designed to address major gaps in the spoken discourse aphasia literature, including a lack of standardization in methodology, analysis, and reporting, as well as nominal data regarding the psychometric properties of spoken discourse outcomes.
Method The initial initiatives for this working group are to (a) propose recommendations regarding standardization of spoken discourse collection, analysis, and reporting in aphasia, based on the results of an international survey and a systematic literature review and (b) create a database of test–retest spoken discourse data from individuals with and without aphasia. The survey of spoken discourse collection, analysis, and interpretation procedures was distributed to clinicians and researchers involved in aphasia assessment and rehabilitation from September to November 2019. We will publish survey results and recommend standards for collecting, analyzing, and reporting spoken discourse in aphasia. A multisite endeavor to collect test–retest spoken discourse data from individuals with and without aphasia will be initiated. This test–retest information will be contributed to a central site for transcription and analysis, and data will be subsequently openly curated.
Conclusion The goal of the working group is to create recommendations for field-wide standards in methods, analysis, and reporting of spoken discourse outcomes, as has been done across other related disciplines (e.g., Consolidated Standards of Reporting Trials, Enhancing the Quality and Transparency of Health Research, Committee on Best Practice in Data Analysis and Sharing). Additionally, the creation of a database through our multisite collaboration will allow the identification of psychometrically sound outcome measures and norms that can be used by clinicians and researchers to assess spoken discourse abilities in aphasia.
Purpose Macrostructural narrative analyses are important clinical measures, revealing age-related declines and disorder-related impairments in the accuracy, completeness, logical sequencing, and organization of content. The current study aims to provide preliminary data on typical aging and psychometric evidence supporting multilevel Main Concept, Sequencing, and Story Grammar (MSSG) analyses that capture these aspects of narratives.
Method Transcripts of Cinderella narratives for 92 healthy control participants stratified across four age brackets from the online database AphasiaBank were coded by Richardson and Dalton (2016) for main concept (MC) analysis. In the current study, MSSG analyses were completed for (a) logical sequencing, independently and in combination with MC accuracy and completeness (MC + sequencing), and (b) story grammar organization (i.e., inclusion of episodic components and complexity of episodes). Interrater agreement (99%–100%) revealed highly reliable scoring.
Results Descriptive statistics for the typically aging sample are presented for sequencing, MC + sequencing, total episodic components, and episodic complexity. Scores for participants over 60 years of age were lower (poorer) than scores for those 20–59 years of age, supporting the construct validity of score use for identifying age-related declines in performance.
Conclusions This study's novel MSSG analyses of narrative production efficiently assess the logical sequencing and story grammar organization of content in healthy controls. Preliminary reliability and validity evidence support the use of all scores to measure age-related changes in narrative macrostructure. Data from this typically aging sample provide a foundation for future research and clinical assessment aimed at quantifying narrative deficits in adults with communication disorders.
Aphasia is an acquired language disorder resulting from a focal brain lesion in the left hemisphere. Language in aphasia is characterized by deficits in lexical retrieval, comprehension of auditory information, repetition and fluency. Verbal output may contain errors in semantic, phonologic, and speech quanta (amount and ease of verbal production). Neuroplasticity in aphasia recovery can be an adaptive process of reactivation or reorganization, but can be maladaptiveand result in persistent errors. Thus, it is important to understand the reorganization of the brain following stroke in terms of adequate and impaired performance. Here we focus on semantics in connected language performance in 22 people with aphasia (PWA) and 18 healthy control participants. Semantics, in this study, is assess in a picture description task for: semantic errors (SE) or paraphasias, significant pauses indicative of lexical retrieval deficits, aphasia severity, and the variety of different types of words used (type-toke ratio, TTR). We investigate the relationship between the brain regions responsible for semantics (a semantic brain network), and how these relationships are altered in aphasia, using resting-state functional magnetic resonance imaging (rsfMRI).
An intensive voice treatment, focused on the respiratory-laryngeal system, affected improved action word production in connected language in individuals with PD. This treatment effect was independent of cognitive status or neuropsychological test performance.
Mental fatigue in healthy individuals is observed under conditions of high cognitive demand, particularly when effort is required to perform a task for a long time – thus fatigue and effort are closely related. In brain injured individuals, mental fatigue can be a persistent and debilitating symptom. Presence of fatigue after brain injury is prognostic for return to work/school and engagement in activities of daily life. As such, it should be a high priority for treatment in this population, but because there is little understanding of its behavioral and neural underpinnings, the target for such treatment is unknown. Here, the neural underpinnings of fatigue and effort are investigated in active duty service members with mild traumatic brain injury (mTBI) and demographically-matched orthopedic controls. Participants performed a Constant Effort task for which they were to hold a predefined effort level constant for long durations during fMRI scanning. The task allowed investigation of the neural systems underlying fatigue and their relationship with sense of effort. While brain activation associated with effort and fatigue did not differentiate the mTBI and controls, functional connectivity amongst active brain regions did. The mTBI group demonstrated immediate hyper-connectivity that increased with effort level but diminished quickly when there was a need to maintain effort. Controls, in contrast, demonstrated a similar pattern of hyper-connectivity, but only when maintaining effort. Connectivity, particularly between the left anterior insula, rostral anterior cingulate cortex, and right-sided inferior frontal regions, correlated with effort-level and state fatigue in mTBI participants. These connections also correlated with effort level in the Control group, but only the connection between the left insula and superior medial frontal gyrus correlated with fatigue, suggesting a differing pattern of connectivity. These findings align, in part, with the dopamine imbalance and neural efficiency hypotheses that pose key roles for medial frontal connections with insular or striatal regions in motivating or optimizing performance. The data propose a complex link between sense of effort, fatigue, and mTBI that is centered in what may be an inefficient neural system due to brain trauma that warrants further investigation.