Methodologies for task-fMRI based prognostic biomarkers in response to aphasia treatment.

With the diversity in aphasia coupled with diminished gains at the chronic phase, it is imperative to deliver effective rehabilitation plans. Treatment outcomes have therefore been predicted using lesion-to-symptom mapping, but this method lacks holistic functional information about the language-network. This study, therefore, aims to develop whole-brain task-fMRI multivariate analysis to neurobiologically inspect lesion impacts on the language-network and predict behavioral outcomes in persons with aphasia (PWA) undergoing language therapy. In 14 chronic PWA, semantic fluency task-fMRI and behavioral measures were collected to develop prediction methodologies for post-treatment outcomes. Then, a recently developed imaging-based multivariate method to predict behavior (i.e., LESYMAP) was optimized to intake whole-brain task-fMRI data, and systematically tested for reliability with mass univariate methods. We also accounted for lesion size in both methods. Results showed that both mass univariate and multivariate methods identified unique biomarkers for semantic fluency improvements from baseline to 2-weeks post-treatment. Additionally, both methods demonstrated reliable spatial overlap in task-specific areas including the right middle frontal gyrus when identifying biomarkers of language discourse. Thus whole-brain task-fMRI multivariate analysis has the potential to identify functionally meaningful prognostic biomarkers even for relatively small sample sizes. In sum, our task-fMRI based multivariate approach holistically estimates post-treatment response for both word and sentence production and may serve as a complementary tool to mass univariate analysis in developing brain-behavior relationships for improved personalization of aphasia rehabilitation regimens.

"There are endless areas that they can use it for": speech-language pathologist perspectives of technology support for aphasia self-management.

BACKGROUND: Aphasia is a debilitating acquired language disorder that often persists as a chronic condition. However, long-term support options are scarce, necessitating the consideration of alternative approaches. Chronic condition self-management approaches, which aim to build self-efficacy and empower people to take responsibility for the day-to-day management of their health condition, may benefit people with aphasia (PwA). Technology is widely used in chronic condition self-management and investigation is required to determine whether it could play a role in aphasia self-management. OBJECTIVE: This study aimed to explore speech-language pathologist (SLP) perspectives on the potential use of technology to support aphasia self-management. METHODS: A qualitative study was conducted with 15 SLPs using semi-structured interviews. Qualitative content analysis was applied to verbatim transcripts to identify codes, categories, and sub-themes which were developed into themes. RESULTS: Three themes were identified: (1) technology supports holistic aphasia self-management by providing additional avenues for service delivery, overall communication, and learning opportunities thus enhancing independence and life participation; (2) SLP and communication partner (CP) assistance can support PwA to use technology for aphasia self-management; (3) considerations and potential barriers to PwA use of technology for aphasia self-management. CONCLUSIONS: Technology can support aphasia self-management by expanding service delivery options, allowing for increased frequency and intensity of therapy practise, and facilitating communication and participation. Personal, professional, and organizational barriers should be addressed in the development of technology-enabled aphasia self-management approaches. SLPs and CPs can offer PwA assistance with technology but may themselves need additional support. Solutions for identified barriers should be considered, such as providing training in the use of technology and implementing aphasia-friendly modifications.IMPLICATIONS FOR REHABILITATIONSelf-management approaches are being explored in the area of aphasia management as a means of offering a holistic, sustainable intervention option that meets the long-term needs of people with aphasia.A range of technology-based resources are currently used in chronic condition self-management and in aphasia therapy, and there are many possibilities for the use of technology in aphasia self-management approaches.Speech-language pathologists identified that technology could facilitate aphasia self-management by expanding service delivery options (e.g., real-time and asynchronous telepractice), enabling increased frequency and intensity of therapy through providing a means of independent practise, offering options for augmentative alternative communication, and enhancing life participation by supporting social communication and daily tasks.,Speech-language pathologists are interested in using technology for aphasia self-management; however, barriers related to organizational policies, individual experience and confidence using technology, and technology itself must be addressed.

The effect of time since stroke, gender, age, and lesion size on thalamus volume in chronic stroke: a pilot study.

Recent stroke studies have shown that the ipsi-lesional thalamus longitudinally and significantly decreases after stroke in the acute and subacute stages. However, additional considerations in the chronic stages of stroke require exploration including time since stroke, gender, intracortical volume, aging, and lesion volume to better characterize thalamic differences after cortical infarct. This cross-sectional retrospective study quantified the ipsilesional and contralesional thalamus volume from 69 chronic stroke subjects' anatomical MRI data (age 35-92) and related the thalamus volume to time since stroke, gender, intracortical volume, age, and lesion volume. The ipsi-lesional thalamus volume was significantly smaller than the contra-lesional thalamus volume (t(68) = 13.89, p < 0.0001). In the ipsilesional thalamus, significant effect for intracortical volume (t(68) = 2.76, p = 0.008), age (t(68) = 2.47, p = 0.02), lesion volume (t(68) = - 3.54, p = 0.0008), and age*time since stroke (t(68) = 2.46, p = 0.02) were identified. In the contralesional thalamus, significant effect for intracortical volume (t(68) = 3.2, p = 0.002) and age (t = - 3.17, p = 0.002) were identified. Clinical factors age and intracortical volume influence both ipsi- and contralesional thalamus volume and lesion volume influences the ipsilesional thalamus. Due to the cross-sectional nature of this study, additional research is warranted to understand differences in the neural circuitry and subsequent influence on volumetrics after stroke.

Lesion symptom mapping of manipulable object naming in nonfluent aphasia: can a brain be both embodied and disembodied?

Embodied cognition offers an approach to word meaning firmly grounded in action and perception. A strong prediction of embodied cognition is that sensorimotor simulation is a necessary component of lexical-semantic representation. One semantic distinction where motor imagery is likely to play a key role involves the representation of manufactured artefacts. Many questions remain with respect to the scope of embodied cognition. One dominant unresolved issue is the extent to which motor enactment is necessary for representing and generating words with high motor salience. We investigated lesion correlates of manipulable relative to nonmanipulable name generation (e.g., name a school supply; name a mountain range) in patients with nonfluent aphasia (N = 14). Lesion volumes within motor (BA4, where BA = Brodmann area) and premotor (BA6) cortices were not predictive of category discrepancies. Lesion symptom mapping linked impairment for manipulable objects to polymodal convergence zones and to projections of the left, primary visual cortex specialized for motion perception (MT/V5+). Lesions to motor and premotor cortex were not predictive of manipulability impairment. This lesion correlation is incompatible with an embodied perspective premised on necessity of motor cortex for the enactment and subsequent production of motor-related words. These findings instead support a graded or "soft" approach to embodied cognition premised on an ancillary role of modality-specific cortical regions in enriching modality-neutral representations. We discuss a dynamic, hybrid approach to the neurobiology of semantic memory integrating both embodied and disembodied components.