Brain plasticity in aphasic patients: Intra- and inter-hemispheric reorganisation of the whole linguistic network probed by N150 and N350 components

The present study examined linguistic plastic reorganization of language through Evoked Potentials in a group of 17 non-fluent aphasic patients who had suffered left perisylvian focal lesions, and showed a good linguistic recovery. Language reorganisation was probed with three linguistic tasks (Phonological, Semantic, Orthographic), the early word recognition potential (N150) and the later phonological-related component (N350). Results showed the typical left-lateralised posterior N150 in healthy controls (source: left Fusiform Gyrus), that was bilateral (Semantic) or right sided (Phonological task) in patients (sources: right Inferior/Middle Temporal and Fusiform Gyri). As regards N350, controls revealed different intra- and inter-hemispheric linguistic activation across linguistic tasks, whereas patients exhibited greater activity in left intact sites, anterior and posterior to the damaged area, in all tasks (sources: Superior Frontal Gyri). A comprehensive neurofunctional model is presented, describing how complete intra- and inter-hemispheric reorganisation of the linguistic networks occurs after aphasic damage in the strategically dominant left perisylvian linguistic centres

Neuroplasticity of language networks in aphasia: advances, updates, and future challenges

Researchers have sought to understand how language is processed in the brain, how brain damage affects language abilities, and what can be expected during the recovery period since the early 19th century. In this review, we first discuss mechanisms of damage and plasticity in the post-stroke brain, both in the acute and the chronic phase of recovery. We then review factors that are associated with recovery. First, we review organism intrinsic variables such as age, lesion volume and location and structural integrity that influence language recovery. Next, we review organism extrinsic factors such as treatment that influence language recovery. Here, we discuss recent advances in our understanding of language recovery and highlight recent work that emphasizes a network perspective of language recovery. Finally, we propose our interpretation of the principles of neuroplasticity, originally proposed by Kleim and Jones (1) in the context of extant literature in aphasia recovery and rehabilitation. Ultimately, we encourage researchers to propose sophisticated intervention studies that bring us closer to the goal of providing precision treatment for patients with aphasia and a better understanding of the neural mechanisms that underlie successful neuroplasticity.P50 DC012283 - NIDCD NIH HHSPublished versio

Aphasia Compendium

Aphasia is an acquired central disorder of language that impairs a person’s ability to understand and/or produce spoken or writing language. The study of aphasia is important in different clinical and fundamental areas, including neurology, psychology, linguistics, and speech-language pathology. This book presents comprehensive information on the diagnosis and treatment of aphasias. Chapters cover such topics as linguistics and the study of aphasias, different types of aphasias, treatment approaches, imaging, and much more

Using visual scene displays to create a shared communication space for a person with aphasia

Background: Low-tech visual scene displays (VSDs) combine contextually rich pictures and written text to support the communication of people with aphasia. VSDs create a shared communication space in which a person with aphasia and a communication partner co-construct messages. Aims: The researchers examined the effect of low-tech VSDs on the content and quality of communicative interactions between a person with aphasia and unfamiliar communication partners. Methods & Procedures: One person with aphasia and nine unfamiliar communication partners engaged in short, one-on-one conversations about a specified topic in one of three conditions: shared-VSDs, non-shared-VSDs, and no-VSDs. Data included discourse analysis scores reflecting the conceptual complexity of utterances, content unit analyses of information communication partners gathered from the interaction, and Likert-scale responses from the person with aphasia about his perception of communicative ease and effectiveness. Outcomes & Results: Comparisons made across conditions revealed: (a) the most conversational turns occurred in the shared-VSDs condition; (b) communication partners produced utterances with higher conceptual complexity in the shared-VSDs condition; (c) the person with aphasia conveyed the greatest number of content units in the shared- VSDs condition; and (d) the person with aphasia perceived that information transfer, ease of conversational interaction, and partner understanding were best in the shared-VSDs condition. Conclusions: These findings suggest that low-tech VSDs have an impact on the manner and extent to which a person with aphasia and a communication partner contribute to conversational interactions involving information transfe

Life interrupted and life regained? Coping with stroke at a young age

Stroke is a leading cause of disability across the developed world, affecting an increasing number of younger people. In this article, we seek to understand the experience of stroke as a disabling life situation among young people and the strategies that they use to recover and cope. Directed content analysis was conducted from interviews with 17 community-dwelling stroke survivors aged 55 years and younger across the United Kingdom. The sample was drawn from a larger maximum variation sample of stroke survivors. Using the sociological concepts of biographical disruption and biographical repair as a guide, excerpts from the interviews pertaining to aspects of the patients’ life that were interrupted, in addition to how they coped with the changes, were selected and analysed. All individuals described an ‘‘altered sense of self,’’ a theme that included loss of identity, family disruption, and/or loss of valued activities. Individuals sought to adapt their sense of self by seeking external support, by restoring normality, and/or through positive reflection. Despite the adapted self that emerged, most individuals continued to experience impairments. While young stroke survivors adapt to their illness over time, they continue to experience impairments and disruptions in their personal and work lives.Aholistic model of rehabilitation that helps individuals regain the capacity for everyday activities related to work, family life, and leisure can begin to address the emotional ramifications of diseases such as stroke, restore wellness, and work towards minimizing the burden felt by family caregivers and children

Life interrupted and life regained? Coping with stroke at a young age

Stroke is a leading cause of disability across the developed world, affecting an increasing number of younger people. In this article, we seek to understand the experience of stroke as a disabling life situation among young people and the strategies that they use to recover and cope. Directed content analysis was conducted from interviews with 17 community-dwelling stroke survivors aged 55 years and younger across the United Kingdom. The sample was drawn from a larger maximum variation sample of stroke survivors. Using the sociological concepts of biographical disruption and biographical repair as a guide, excerpts from the interviews pertaining to aspects of the patients’ life that were interrupted, in addition to how they coped with the changes, were selected and analysed. All individuals described an ‘‘altered sense of self,’’ a theme that included loss of identity, family disruption, and/or loss of valued activities. Individuals sought to adapt their sense of self by seeking external support, by restoring normality, and/or through positive reflection. Despite the adapted self that emerged, most individuals continued to experience impairments. While young stroke survivors adapt to their illness over time, they continue to experience impairments and disruptions in their personal and work lives.Aholistic model of rehabilitation that helps individuals regain the capacity for everyday activities related to work, family life, and leisure can begin to address the emotional ramifications of diseases such as stroke, restore wellness, and work towards minimizing the burden felt by family caregivers and children

Neurocognitive screening following acquired brain injury: an adaptation of the Birmingham Cognitive Screen for Zimbabwe (Zim-BCoS)

Neuropsychology as a discipline has not taken root in low- and middle-income countries. Most neurocognitive tests used in these countries were developed and normed in high-income, mostly western countries. The psychometric robustness of these tests is often weak when they are used on low to middle-income clinical populations. The objectives of this study were to select, adapt and generate normative data for a suitable neurocognitive screen for use in Zimbabwe. To achieve these objectives, we divided the study into 4 phases. In Phase 1 of the study, we did a systematic review that identified 83 neurocognitive assessment instruments commonly used in low- and middle-income countries on patients who have suffered a stroke. From these instruments, we selected, adapted and normed the Birmingham Cognitive Screen (BCoS; Humphreys al., 2012) through phases 2 to 4 of this study. The screen offers a robust and sufficiently broad but shallow assessment tool for cognitive deficits across key cognitive domains commonly impaired following a stroke. In particular, in Phase 2 of the study, we evaluated the cross-cultural sensitivity of BCoS on healthy participants (N=105). We then performed surveys using the Delphi method on a panel of experts to culturally adapt BCoS for use in Zimbabwe (Zim-BCoS). We evaluated the inter-rater and test-retest reliability of the translated and validated Zim-BCoS and also compared its agreement with the original BCoS version to determine its robustness. In Phase 3, we evaluated the effects of demographic variables on performance on the cognitive domains assessed by Zim-BCoS. To do this, we performed multiple linear regression analyses to calculate regression-based norms using scores from a sample of healthy participants (N=412). From these analyses, participants' age, level of education and sex had significant effects, mainly on subtests in the language cognitive domain (Picture Naming, Sentence/Word Reading/Writing and Instruction Comprehension). In Phase 4 of the study, we performed neurocognitive assessments using Zim-BCoS (and other tests) to assess and determine the frequency of specific neurocognitive deficits in patients who had suffered a stroke and were attending two major hospitals in Harare, Zimbabwe's capital city (N=103). We also compared the performance of these patients to a matched control sample (N=103). To determine the psychometric stability of Zim-BCoS we determined its validity and reliability by comparing scores on its subtests to parallel neurocognitive tests that assess similar cognitive domains. We also assessed the predictive value of Zim-BCoS on patients' neuropsychiatric and functional outcomes. We evaluated the convergence and predictive validity as well as the inclusivity of Zim-BCoS to assess patients with aphasia. We used the Zim-BCoS test scores to establish prevalence rates of cognitive deficits and other post-stroke sequelae in the sample of patients with stroke. We also assessed the predictive value of ZimBCoS subtests on patients' neuropsychiatric and functional outcomes. All comparisons of ZimBCoS against standard cognitive tests and post-stroke sequelae measures had statistically significant convergence, predictive validity and inclusivity. In this study, we demonstrated the utility of Zim-BCoS for assessing cognitive impairment in patients who have suffered a stroke, particularly in resource poor contexts typical of low-income countries. We concluded that ZimBCoS is a robust neuropsychological screen suitable for research and clinical use in Zimbabwe. The screen has the potential to offer a cost effective and easy to use neurocognitive screen for patients with acquired neurological changes in low-income countries in Southern Africa

Mapping therapy for sentence production impairments in nonfluent aphasia

This study investigated a new treatment in which sentence production abilities were trained in a small group of individuals and nonfluent aphasia. It was based upon a mapping therapy approach which holds that sentence production and comprehension impairments are due to difficulties in mapping between the meaning form (thematic roles) and the syntactic form of sentences. We trained production of both canonical and noncanonical reversible sentences.Three patients received treatment and two served as control participants. Patients who received treatment demonstrated acquisition of all trained sentence structures. They also demonstrated across-task generalisation of treated and some untreated sentence structures on two tasks of constrained sentence production, and showed some improvements on a narrative task. One control participant improved on some of these measures and the other did not. There was no noted improvement in sentence comprehension abilities following treatment. Results are discussed with reference to the heterogeneity of underlying impairments in sentence production impairments in nonfluent patients, and the possible mechanisms by which improvement in sentence production might have been achieved in treatment

Campus & alumni news

Boston University Medicine was published by the Boston University Medical Campus, and presented stories on events and topics of interest to members of the BU Medical Campus community. It followed the discontinued publication Centerscope as Boston University Medicine from 1991-2005, and was continued as Campus & Alumni News from 2006-2013 before returning to the title Boston University Medicine from 2014-present