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Background: Clinical guidelines recommend the administration of intravenous recombinant tissue plasminogen activator thrombolytic treatment to persons who suffered ischemic stroke within 4,5 hours since onset. However, the available evidence on the potential improvement of language after thrombolysis is still scanty. Aims: This study assessed the effect of thrombolytic treatment in language recovery in persons with stroke aphasia (PWA) comparing the efficacy of traditional language assessments and a multilevel procedure of discourse analysis applied to the Cookie Theft picture descriptions taken from the National Institute of Health Stroke Scale (NIHSS). Methods and procedures: Fortyeight individuals participated in the study: sixteen PWA who received thrombolysis; sixteen PWA who did not receive it; sixteen healthy controls. The two groups of PWA were balanced in terms of age, education, gender, lateralization of the lesion, and stroke severity. They were administered the NIHSS and a bedside language assessment battery when entering the neurological clinic (T0) and after approximately 72 hours (T1). Their narrative discourse descriptions were analyzed with a multilevel procedure for discourse analysis. Outcomes and results: The two groups of PWA had similar linguistic difficulties at T0 as reflected by comparable Composite Verbal Scores and performance on traditional linguistic bedside assessment (Aphasia PostStroke Acute Assessment test; Furlanis et al., 2018). Discourse analysis highlighted the presence of more omissions of function words and errors of cohesion in the PWA who would receive thrombolysis with respect to healthy controls and allowed for the identification, in both groups, of difficulties that could not be detected through a traditional assessment. At T1 the analyses showed the presence of improvements likely reflecting a generalized spontaneous recovery in both groups of PWA and a more specific recovery triggered by thrombolysis concerning the production of global coherence errors in treated patients only. An inspection of the gravity of the linguistic symptoms at the individual level revealed high interindividual variability in this early phase suggesting that thrombolysis reduced the severity of the impairment also in the production of informative words. Conclusions: Thrombolysis reduces the gravity of some linguistic symptoms within a few hours after treatment. Multilevel procedures of discourse analysis can identify these subtle improvements. [ABSTRACT FROM AUTHOR]

[Display omitted] • List the causes of aphasia after basal ganglia stroke • A variety of imaging techniques for post-basal ganglia aphasia detection are described, including their advantages and disadvantages are highlighted • The magnetic stimulation technique that can be used for the treatment of aphasia in basal ganglia stroke is briefly introduced, and its advantages and disadvantages are highlighted • Looking forward to the future development direction of basal ganglia stroke aphasia detection and treatment Post-stroke basal ganglia aphasia is an unusual and transient form of aphasia resulting from basal ganglia damage. It is commonly believed that the generation of language function primarily resides in regular language regions of the brain; however, recent findings indicate a prevalence of basal ganglia stroke aphasia as high as 22%. Subcortical structures (e.g., basal ganglia) also play an important role in language processing. Aphasia seriously affects the quality of life and functional outcomes of patients, and early diagnosis and intervention are important for the prognosis of and rehabilitation from aphasia after basal ganglia stroke. In recent years, the main diagnostic methods for basal ganglia aphasia include diffusion tensor imaging, diffusion spectral imaging, and functional magnetic resonance imaging, which explore the changes in patients with basal ganglia aphasia compared to those without from the perspectives of fiber tract imaging and brain function alteration, respectively, and are able to predict the recovery of patients before and after treatment. Treatment for post-stroke basal ganglia aphasia includes transcranial magnetic stimulation, a recent emerging therapeutic technique, in addition to conventional medications and speech rehabilitation. Consequently, understanding this condition is crucial. This review delves into its causes, imaging methods, and therapeutic interventions, offering a systematic and comprehensive analysis of these aspects. [ABSTRACT FROM AUTHOR]

Post-stroke language recovery remains one of the main unresolved topics in the field of aphasia. In recent years, there have been efforts to identify specific factors that could potentially lead to improved language recovery. However, the exact relationship between the recovery of particular language functions and possible predictors, such as demographic or lesion variables, is yet to be fully understood. In the present study, we attempted to investigate such relationships in 42 patients with aphasia after left hemisphere stroke, focusing on three language domains: auditory comprehension, naming and speech fluency. Structural imaging data were also obtained for the identification of the lesion sites. According to our findings, patients demonstrated an overall improvement in all three language domains, while no demographic factor significantly contributed to aphasia recovery. Interestingly, specific lesion loci seemed to have a differential effect on language performance, depending on the time of testing (i.e., acute/subacute vs. chronic phase). We argue that this variability concerning lesion–deficit associations reflects the dynamic nature of aphasia and further discuss possible explanations in the framework of neuroplastic changes during aphasia recovery. [ABSTRACT FROM AUTHOR]

Poststroke aphasia typically results from brain damage to the left‐lateralized language network. The contribution of the right‐lateralized homologues in aphasia recovery remains equivocal. In this longitudinal observational study, we specifically investigated the role of right hemisphere structural connectome in aphasia recovery. Twenty‐two patients with aphasia after a left hemispheric stroke underwent comprehensive language assessment at the early subacute and chronic stages. A novel structural connectometry approach, using multi‐shell diffusion‐weighted MRI data collected at the early subacute stage, was used to evaluate the relationship between right hemisphere white matter connectome and language production and comprehension abilities at early subacute stage. Moreover, we evaluated the relationship between early subacute right hemisphere white matter connectome and longitudinal change in language production and comprehension abilities. All results were corrected for multiple comparisons. Connectometry analyses revealed negative associations between early subacute stage right hemisphere structural connectivity and language production, both cross‐sectionally and longitudinally (pFDR <.0125). In turn, only positive associations between right hemisphere structural connectivity and language comprehension were observed, both cross‐sectionally and longitudinally (pFDR <.0125). Interhemispheric connectivity was highly associated with comprehension scores. Our results shed light on the discordant interpretations of previous findings, by providing evidence that while some right hemisphere white matter pathways may make a maladaptive contribution to the recovery of language, other pathways support the recovery of language, especially comprehension abilities. [ABSTRACT FROM AUTHOR]

We examined the extent of L1 vocabulary attrition in a Korean child following her relocation to the United States at the age of 6 years 10 months, and the subsequent restoration of her L1 vocabulary upon her return to Korea 10 months later.A picture-naming task was administered on a regular basis over a period of several months, beginning shortly after the child’s arrival in the United States.The data were analyzed to determine the child’s accuracy in producing common nouns in the L1.The study shows significant L1 vocabulary attrition after just 1 month, with an inability to access half of the test items after just 4 months and a drop in accuracy to 25% after 9 months. Upon return to Korea, the child’s L1 vocabulary improved rapidly, surpassing English usage within 3 weeks and reaching 82% accuracy within 6 weeks. These findings underscore the vulnerability of children to language attrition in a monolingual environment while also highlighting the remarkable resilience of their L1 skills.The study traced the child’s L1 decline and recovery in accordance with a strict timetable. By beginning measurements within a week of the child’s exposure to English following her subsequent reintroduction to Korean, the study was able to document the earliest manifestations of lexical attrition, its rapid progression, and its subsequent reversal—a pattern of decline and recovery that is rarely studied in this manner.This study contributes to the field by systematically documenting the impact on L1 vocabulary of a sudden change in linguistic environment, providing rare insights into the dynamics of lexical attrition in early bilingualism. [ABSTRACT FROM AUTHOR]

Purpose: Aphasia—acquired loss of the ability to understand or express language—is a common and debilitating neurological consequence of stroke. Evidence suggests that transcranial magnetic stimulation (TMS) can significantly improve language outcomes in patients with aphasia. Repetitive transcranial magnetic stimulation (rTMS) has been reported to improve naming in chronic stroke patients with nonfluent aphasia since 2005. Methods: We conducted a systematic review and meta-analyses of TMS treatment studies in patients with aphasia. Eight electronic databases (PubMed, Medline, Embase, Scopus, ScienceDirect, Cochrane Central Register of Controlled Trials, Journals@Ovid, and clinicaltrials.gov) were searched for articles. Relevant studies were further evaluated, and studies that met inclusion criteria were reviewed. The searches were limited to human studies written in English and published between January 1960 and January 2020. In keeping with the main objective of this review, we included all studies that carried out treatment using rTMS in stroke patients with aphasia, regardless of the trial (or experimental) design of the study. Studies that implemented between-subject or randomized controlled (RCT) design, cross-over trials, and within-subject or pre-post trials were all included. Standard mean difference (SMD) for changes in picture naming accuracy was estimated. Results: The literature search yielded 423 studies. Fifty articles were further evaluated to be included. Eleven met all inclusion criteria and were chosen for review. Eleven eligible studies involving 242 stroke patients were identified in this meta-analysis. Further analyses demonstrated prominent effects for the naming subtest (SMD = 1.26, 95% CI = 0.80 to 1.71, p = 0.01), with heterogeneity (I2 = 69.101%). The meta-analysis continued to show that there was a statistically significant effect of rTMS compared with sham rTMS on the severity of aphasia. None of the patients from the 11 included articles reported adverse effects from rTMS. Conclusions: There are some strong studies evaluating the efficacy of rTMS in stroke patients but further research is required to fully establish the usefulness of this treatment. This meta-analysis indicates a clinically positive effect of rTMS with or without speech and language therapy (SLT) for patients with aphasia following stroke in overall language function and expressive language, including naming, repetition, writing, and comprehension. Low-frequency (1 Hz) rTMS over the unaffected hemisphere is effective and compatible with the concept of interhemispheric inhibition. Moreover, the treatment of 1 Hz rTMS for patients with aphasia after stroke was safe. [ABSTRACT FROM AUTHOR]

Previous findings have demonstrated the importance of discourse analysis in post-stroke aphasia, as it allows for in-depth examination of language impairment and represents key components of functional communication. However, little is known about the recovery of discourse over time. The main aim of this study is to measure the longitudinal changes in descriptive discourse production from the acute to chronic stages of post-stroke aphasia recovery. The secondary aim is to explore the association between discourse measures and overall language impairment severity measures at different testing points. Seventeen French-Canadian speakers with various types and severities of aphasia following a first left middle cerebral artery stroke participated in this study. They underwent three language assessments (acute: 0 to 72 hours; subacute: 7 to 14 days; chronic: 6 to 12 months post-onset). The picture description from the Western Aphasia Battery was analyzed at three time points. Changes in terms of thematic informativeness and microstructural variables were analyzed. Regarding the micro-structural variables, the mean length of utterances (MLU) and the number of words per minute showed significant positive changes between the acute and chronic phases. For the thematic informativeness measures, the number of thematic units (TUs), the number of thematic units per minute (TUs/min) and the number of thematic units per utterance (TUs/utt) increased significantly between the acute and chronic phases. Positive correlations between TUs and MLU in the acute phase and a general language impairment severity measure in the acute and chronic phases suggest a relationship between these measures and global language performance suggesting the potential predictive value of these variables in the acute phase. These findings support the use of thematic units in descriptive discourse analysis during an acute clinical examination of language as they require minimal additional time to score and track changes in post-stroke aphasia recovery. They capture long-term changes in discourse abilities and appear related to overall language measures in both the acute and chronic stages of recovery. The interpretation of the changes in MLU and the number of words per minute is less straightforward, as improvements in these measures carry different interpretations depending on the type of aphasia. Nonetheless, further studies are required to investigate test-retest reliability and the effect of therapy on the changes observed over time when using thematic units to document change in discourse. [ABSTRACT FROM AUTHOR]

Background & Objective: Aphasia—acquired loss of the ability to understand or express language—is a common and debilitating neurological consequence of stroke. Evidence suggests that transcranial magnetic stimulation (TMS) can significantly improve language outcomes in patients with aphasia. Repetitive transcranial magnetic stimulation (rTMS) has been reported to improve naming in chronic stroke patients with nonfluent aphasia since 2005. Methods: We conducted a systematic review and meta-analyses of TMS treatment studies in patients with aphasia. Eight electronic databases (PubMed, Medline, Embase, Scopus, ScienceDirect, Cochrane Central Register of Controlled Trials, Journals@ Ovid, and clinicaltrials.gov) were searched for articles. Relevant studies were further evaluated and studies that met inclusion criteria were reviewed. We included studies if were: randomized controlled blinded clinical trials, meta-analyses or crossover designs of rTMS alone or with speech therapy or any other therapy tested with rTMS. Standard mean difference (SMD) for changes in picture naming accuracy was estimated. Results: The literature search yielded 423 studies. Fifty articles were further evaluated to be included. Eleven met all inclusion criteria and were chosen for review. Eleven eligible studies involving 301 stroke patients were identified in this meta-analysis. Further analyses demonstrated prominent effects for the naming subtest (SMD = 1.26, 95% CI = 0.80 to 1.71, P=0.01), with heterogeneity (I2 = 69.101%). The meta-analysis continued to show that there was a statistically significant effect of rTMS compared with sham rTMS on the severity of aphasia. None of the patients from the 11 included articles reported adverse effects from rTMS. Conclusions: There are some strong studies evaluating the efficacy of rTMS in stroke patients but further research is required to fully establish the usefulness of this treatment. This meta-analysis indicates a clinically positive effect of rTMS with or without speech and language therapy (SLT) for patients with aphasia following stroke in overall language function and expressive language, including naming, repetition, writing, and comprehension. Low-frequency (1 Hz) rTMS over the unaffected hemisphere is effective and compatible with the concept of interhemispheric inhibition. Moreover, the treatment of 1 Hz rTMS for patients with aphasia after stroke was safe. [ABSTRACT FROM AUTHOR]

Background: Stroke-like migraine attacks after radiation therapy – also known as SMART syndrome – constitute a rare condition characterised by headache, seizures, vision abnormalities, hemiparesis, and aphasia. The condition usually resolves within a few days or weeks with little to no residual impairment; however, recovery in some cases is protracted and incomplete. Aims: The purpose of this case report was to describe the one-year progression of language in a person, GB, with slow recovery from SMART syndrome. Methods & Procedures: GB was diagnosed with SMART syndrome at 39 years of age. Formal and informal assessments occurred at six, 11, 18, 29, and 52 weeks post-onset of SMART syndrome. Standardised assessment involved administration of portions of the Western Aphasia Battery – Revised, and informal assessment took the form of written and spoken language sample analyses. Outcomes & Results: Initial evaluation at two weeks post-onset revealed global aphasia. This evolved into severe Wernicke's aphasia by six weeks post-onset. Repeated evaluation over subsequent months revealed gradual improvement but continuing and substantial language impairment. At one-year post-onset, GB displayed anomic aphasia and persistent reading and writing deficits. Conclusions: Substantial language recovery from SMART syndrome can occur beyond the initial few months post-onset. Documentation of the nature and extent of language impairment provides a starting point for developing and refining efficacious treatment protocols. [ABSTRACT FROM AUTHOR]

Increasing clinical and scientific attention is given to the transition of neurological stages from child to adult. Data on brain plasticity during adolescence is interesting for providing adequate evidence-based medical attention to neurological conditions in this population. Acquired aphasia is well described in adults and children, but not in adolescence. We describe a 5-year follow-up of language in three adolescent subjects with post-brain injury aphasia. We analysed and scored formal aspects of language three times, language hemispheric dominance twice with dichotic listening test and functional magnetic resonance imaging (fMRI) brain activation patterns that supported expressive and comprehensive language during the recovery period. We found similarities to both paediatric and adult aphasia in these three adolescents. While the level of recovery resembled that of children with aphasia, a more efficient language rehabilitation occurred in those who remained with left hemispheric dominance in the chronic stage, as it is reported in adults. Our analysis and long-term follow-up provide data for a better understanding on how the injured brain matures during adolescence. More studies with larger samples will help to understand the function of the remaining networks and the recovery from injury in this particular age group. [ABSTRACT FROM AUTHOR]

Understanding the processes underlying normal, impaired, and recovered language performance has been a long-standing goal for cognitive and clinical neuroscience. Many verbally described hypotheses about language lateralization and recovery have been generated. However, they have not been considered within a single, unified, and implemented computational framework, and the literatures on healthy participants and patients are largely separated. These investigations also span different types of data, including behavioral results and functional MRI brain activations, which augment the challenge for any unified theory. Consequently, many key issues, apparent contradictions, and puzzles remain to be solved. We developed a neurocomputational, bilateral pathway model of spoken language production, designed to provide a unified framework to simulate different types of data fromhealthy participants and aphasic patients. The model encapsulates key computational principles (differential computational capacity, emergent division of labor across pathways, experience-dependent plasticityrelated recovery) and provides an explanation for the bilateral yet asymmetric lateralization of language in healthy participants, chronic aphasia after left rather than right hemisphere lesions, and the basis of partial recovery in patients. The model provides a formal basis for understanding the relationship between behavioral performance and brain activation. The unified model is consistent with the degeneracy and variable neurodisplacement theories of language recovery, and adds computational insights to these hypotheses regarding the neural machinery underlying language processing and plasticityrelated recovery following damage. [ABSTRACT FROM AUTHOR]

The „Euskaldización" is one of the keys of the Basque Country's language policy. Based on its territorial autonomy the Autonomous Community of Euskadi since about 40 years has made significant progress in the recovery of its own language in every sector of life. A short assessment of the most important features of this process and an outlook on future developments. [ABSTRACT FROM AUTHOR]

Background: Discourse analysis allows the examination of functional and ecological language impairment in post-stroke aphasia. Given its complexity, various methods of analysis have been developed to measure the multiple components of discourse. Clinical assessment usually includes discourse analysis, but how clinicians should assess recovery of discourse, particularly in acute care settings, is still a matter of debate. Aims: This study aimed to measure improvements in discourse production in early post-stroke aphasia recovery. Methods & Procedure: Twenty-three persons with aphasia following a first left middle cerebral artery stroke were recruited in the stroke unit of Hôpital du Sacré-Coeur de Montréal (May 2015-July 2018). Patients treated with thrombolysis (n = 10) and untreated patients underwent two aphasia assessments (0 to 72 hours, 7 to 14 days post-onset). Discourse assessment consisted of the picture description task from the Western Aphasia Battery. Changes in microlinguistic and thematic informativeness measures between the two assessment periods were analyzed. Outcomes & Results: In-depth microlinguistic analyses showed no significant difference between the initial and follow-up assessments. Conversely, some thematic informativeness variables improved significantly during the same time period. Patients treated with thrombolysis produced more thematic units than untreated patients at both assessments, but the change between the two groups was not significant. Conclusions & Implications: This study suggests that thematic informativeness variables are sensitive to language improvement in early post-stroke aphasia recovery whereas no microlinguistic variables improved significantly in the same period. In contrast to previous evidence, the difference between patients treated with thrombolysis and untreated patients was not evident over time. The results suggest that thematic informativeness constitutes an interesting path to explore as a routine clinical assessment in acute-care settings because it is time-efficient, simple to conduct and reliable in assessing early changes in the discourse production of individuals with aphasia in the acute post-stroke phase. [ABSTRACT FROM AUTHOR]

To study the clinical effect and fine nursing of transsylvian approach for surgical treatment of cerebral hemorrhage under microscope, in this study, 53 hospitalized patients with hypertensive cerebral hemorrhage from February 1, 2016 to December 31, 2018 are selected as experimental subjects. According to the patient's condition, they are divided into sylvius group (27 cases) and temporal lobe group (26 cases). Two groups of patients are operated on, and the volume of brain edema, language recovery and advanced distributed learning (ADL) score are observed. The results show that in the analysis of patients' basic condition, there is no significant difference in age and gender between the two groups of patients (P > 0.05). The clearance of hematoma, glasgow coma scale (GCS) score and dominant brain of the two groups are compared and analyzed. No significant difference is found between the patients in sylvius group and the temporal lobe group (P > 0.05). After comparing and analyzing the volume of brain edema between the two groups, it is found that the volume of brain edema in the sylvius group was smaller than that in the temporal lobe group, with statistical difference (P < 0.05). After comparing and analyzing the language recovery ability of the two groups, it is found that the recovery of hearing, speaking, reading and writing ability of the temporal lobe group is worse than that of the sylvius group, and there is significant difference between the sylvius group and the temporal lobe group (P < 0.01). In ADL score after operation, it was found that the score of temporal lobe group was significantly lower than that of sylvius group and there is significant difference between the two groups (P < 0.01). Therefore, through this study, it is found that after different surgical treatments, the prognosis of transsylvian approach for surgical treatment is better, which achieves the desired results. Although there are still some shortcomings in the experimental process, it still provides experimental basis for the clinical treatment of patients with hypertensive cerebral hemorrhage in the later stage, and has important research significance. [ABSTRACT FROM AUTHOR]

Objective: To review the research literature pertaining to post-stroke language recovery, and to discuss neurocognitive assessment in patients in the context of aphasia, time course of language recovery, factors associated with language recovery, and therapeutic techniques designed to facilitate language recovery. Method: Articles were identified through PubMed, MEDLINE, PsychINFO, and Google Scholar searches. Examples of utilized keywords include "post-stroke aphasia," "post-stroke language recovery," "post-stroke neurocognitive assessment," and "neuropsychology and aphasia." Results: Most language recovery occurs in the first few weeks following stroke, but residual recovery may occur for many years. Although initial aphasia severity is the single largest determinant of post-stroke language recovery, a number of other variables also contribute. Several techniques have been developed to aid in the recovery process including speech-language therapy and noninvasive brain stimulation, although the effectiveness of acute and subacute treatment remains unclear. Some degree of valid neurocognitive assessment is possible in patients with aphasia, and the information gained from such an evaluation can aid the rehabilitative process Conclusions: Significant recovery of language function is possible following a stroke, but prediction of level of recovery in an individual patient is difficult. Information about initial aphasia severity and the integrity of cognitive domains other than language can help guide the rehabilitation team, as well as manage expectations for recovery. [ABSTRACT FROM AUTHOR]

Background: Bilingual aphasia forms a significant part of speech-language pathologists' (SLP) caseload, globally, and specifically in South Africa. Few tools supporting clinical decision-making are available due to limited understanding of typical and disordered cross-linguistic processing (how the languages interact). Speech errors may provide insight about "hidden" bilingual mechanisms. Objectives: To determine what speech errors can impart about cross-linguistic processing, as well as, associated language and impairment variables in Sepedi-English individuals with aphasia. Method: The case series included six participants, purposively selected from three rehabilitation sites in South Africa. Detailed language and clinical profiles were obtained. Participants performed a confrontation naming task in their most dominant (MDL) and less dominant language (LDL). Responses were audio recorded, transcribed, and analyzed for overall accuracy and error type in MDL and LDL; verified by a Sepedi-speaking linguist and a qualified SLP. Results: (1) No statistically significant differences in MDL-LDL naming accuracy were found, supporting recent literature of simultaneous inter-activation of both languages and shared word retrieval mechanisms. All types of speech errors occurred, and semantic errors were produced most frequently and consistently in each participant's MDL and LDL. (2) Language proficiency, language recovery patterns, and aphasia type (Broca's and Anomic) and severity (mild and/or moderate) appeared to be more strongly linked to cross-linguistic processing than Sepedi-English linguistic differences and age of acquisition of both languages. Conclusions: Participants with bilingual aphasia may use typical cross-linguistic and word retrieval mechanisms, concurring with current theories of bilingualism. Findings are preliminary, warranting investigations of other language tasks, modalities, pairs, and related variables. [ABSTRACT FROM AUTHOR]

The learning of writing skills involves the re-engagement of previously established independent procedures. Indeed, the writing deficit an adult may acquire after left hemispheric brain injury is caused by either an impairment to the lexical route, which processes words as a whole, to the sublexical procedure based on phoneme-to-grapheme conversion rules, or to both procedures. To date, several approaches have been proposed for writing disorders, among which, interventions aimed at restoring the sub-lexical procedure were successful in cases of severe agraphia. In a randomized double-blind crossover design, fourteen chronic Italian post-stroke aphasics underwent dual transcranial direct current stimulation (tDCS) (20 min, 2 mA) with anodal and cathodal current simultaneously placed over the left and right temporo-parietal cortex, respectively. Two different conditions were considered: (1) real, and (2) sham, while performing a writing task. Each experimental condition was performed for ten workdays over two weeks. After real stimulation, a greater amelioration in writing with respect to the sham was found. Relevantly, these effects generalized to different language tasks not directly treated. This evidence suggests, for the first time, that dual tDCS associated with training is efficacious for severe agraphia. Our results confirm the critical role of the temporo-parietal cortex in writing skills.

Stroke in the language dominant hemisphere is the most frequent cause of aphasia. In the course of post-stroke aphasia different mechanisms can contribute to the recovery of language: recovery from ischemia, compensatory rerouting of language modalities and neuroplasticity occur at different time scales after the initial injury. These mechanisms may occur spontaneously or may be induced or influenced by various therapeutic interventions. This report contains a systematic review of the literature concerning the debated role of the right hemisphere in the recovery from stroke-related aphasia. The existing literature was approached using the PICOS principle and well-established inclusion and exclusion criteria. Although many gaps remain in the knowledge on the role of the right hemisphere, there is some evidence of a facilitation of spontaneous language recovery in the acute and subacute phase. In the subacute and chronic phase, the right hemisphere homologous language areas, along with memory and attention-related areas, facilitate treatment related improvement. In contrast, in therapy-free periods in the chronic stage, the right hemisphere no longer contributes to language recovery or may even be inhibitory. Injury-, language- and therapy-related variables impact on the role of the right hemisphere in aphasia recovery. [ABSTRACT FROM AUTHOR]

BACKGROUND: Noninvasive transcranial stimulation methods have been increasingly employed in order to improve cognitive performance in neurological patients. In previous studies with both stroke patients and healthy subjects, noninvasive stimulation of temporal-parietal regions and their homologue produced an improvement in linguistic tasks. OBJECTIVE: The aim of the current study was to evaluate if anodal transcranial direct current stimulation (tDCS) over Brodmann areas 39/40 (angular and supramarginal gyri) could promote the recovery of linguistic functions, in particular comprehension and naming, in a single patient affected by dementia. METHODS: Three preliminary explorative single sessions (right-side anodal, left-side anodal and sham tDCS) were carried out (Experiment 1). This procedure allows targeting the more effective site of stimulation for the treatment. Subsequently, we carried out a five-days tDCS treatment on the selected hemisphere (Experiment 2). RESULTS: We report verb comprehension amelioration after 5 days of anodal tDCS over the right BAs 39/40 compared with the placebo tDCS. This result is maintained until two weeks after the end of the 5-days treatment. CONCLUSIONS: Our findings provide new evidence for the therapeutic use of tDCS in degenerative diseases, suggesting that an explorative study can be useful for targeting the more appropriate stimulation site and confirm the involvement of right-sided areas associated with language activities. [ABSTRACT FROM AUTHOR]

The neural networks involved in language recovery following hemispherotomy of the dominant hemisphere after language acquisition in children remain poorly known. Twelve hemispherotomized children (mean age at surgery: 11.3 years) with comparable post-operative neuropsychological patterns underwent multi-task language functional MRI. Three of them had recovered from an initial postoperative aphasia i.e., hemispherotomy was performed on the language-dominant hemisphere. Our main results revealed (1) perisylvian activations in all patients after either left or right hemispherotomy; (2) no differences in activations between groups regarding the side of hemispherotomy; (3) additional activations in pre-frontal (3/3) and hippocampal/parahippocampal and occipito-parietal (2/3) areas, when comparing language activation in each of the three subjects with hemispherotomy of the language-dominant hemisphere to the group of 9 non-dominant hemispherotomized patients. These neural networks support the stronger engagement of learning and memory during language recovery in a hemisphere that was not initially actively subserving language. [ABSTRACT FROM AUTHOR]

Current theories of language recovery after stroke are limited by a reliance on small studies. Here, we aimed to test predictions of current theory and resolve inconsistencies regarding right hemispheric contributions to long-term recovery. We first defined the canonical semantic network in 43 healthy controls. Then, in a group of 43 patients with chronic post-stroke aphasia, we tested whether activity in this network predicted performance on measures of semantic comprehension, naming, and fluency while controlling for lesion volume effects. Canonical network activation accounted for 22%-33% of the variance in language test scores. Whole-brain analyses corroborated these findings, and revealed a core set of regions showing positive relationships to all language measures. We next evaluated the relationship between activation magnitudes in left and right hemispheric portions of the network, and characterized how right hemispheric activation related to the extent of left hemispheric damage. Activation magnitudes in each hemispheric network were strongly correlated, but four right frontal regions showed heightened activity in patients with large lesions. Activity in two of these regions (inferior frontal gyrus pars opercularis and supplementary motor area) was associated with better language abilities in patients with larger lesions, but poorer language abilities in patients with smaller lesions. Our results indicate that bilateral language networks support language processing after stroke, and that right hemispheric activations related to extensive left hemispheric damage occur outside of the canonical semantic network and differentially relate to behavior depending on the extent of left hemispheric damage. Hum Brain Mapp 38:1636-1658, 2017. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Aphasia is a language disorder affecting more than one million people in the US. While language function has traditionally been the focus of neuroimaging research, other cognitive functions are affected in this population, which has implications not only for those specific processes but also for the interaction of language and other cognitive functions. Resting state fMRI (rs-fMRI) is a practical and informative way to explore and characterize general cognitive engagement and/or health in this population, but it is currently underutilized. The aim of this study was to explore the functional connectivity in resting state networks (RSNs) and in the semantic network in seven persons with aphasia (PWA) who were at least 6 months post onset compared with 11 neurologically healthy adults (NHA) in order to gain a more comprehensive understanding of general cognitive engagement in aphasia. These preliminary results show that PWA exhibit hypoconnectivity in the semantic network and all RSNs except the visual network. Compared with NHA, PWA appear to have fewer cross- and left-hemispheric connections. However, PWA exhibit some stronger connections than NHA within the semantic network, which could indicate compensatory mechanisms. Importantly, connectivity for RSNs appear to increase with decreasing aphasia severity and decrease with increasing lesion size. This knowledge has the potential to improve aphasia therapy by furthering the understanding of lesion effects on the cognitive system as a whole, which can guide treatment target selection and promotion of favorable neural reorganization for optimal recovery of function. [ABSTRACT FROM AUTHOR]

Using magnetoencephalography, we investigated the potential of perilesional and contralesional activity to support language recovery in patients with poststroke aphasia. In healthy young controls, left-lateralized ventral frontotemporal regions responded to semantic anomalies during sentence comprehension and bilateral dorsal frontoparietal regions responded to syntactic anomalies. Older adults showed more extensive bilateral responses to the syntactic anomalies and less lateralized responses to the semantic anomalies, with decreased activation in the left occipital and parietal regions for both semantic and syntactic anomalies. In aphasic participants, we observed compensatory recruitment in the right hemisphere (RH), which varied depending on the type of linguistic information that was processed. For semantic anomalies, aphasic patients activated some preserved left hemisphere regions adjacent to the lesion, as well as homologous parietal and temporal RH areas. Patients also recruited right inferior and dorsolateral frontal cortex that was not activated in the healthy participants. Responses for syntactic anomalies did not reach significance in patients. Correlation analyses indicated that recruitment of homologous temporoparietal RH areas is associated with better semantic performance, whereas higher accuracy on the syntactic task was related to bilateral superior temporoparietal and right frontal activity. The results suggest that better recovery of semantic processing is associated with a shift to ventral brain regions in the RH. In contrast, preservation of syntactic processing is mediated by dorsal areas, bilaterally, although recovery of syntactic processing tends to be poorer than semantic. Hum Brain Mapp 37:2869-2893, 2016. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Purpose: Aphasia--acquired loss of the ability to understand or express language--is a common and debilitating neurological consequence of stroke. Evidence suggests that transcranial magnetic (TMS) or direct current stimulation (tDCS) can significantly improve language outcomes in patients with aphasia (PWA). However, the relative efficacy between TMS and tDCS has not yet been explored. Mechanistic and methodological differences, patient inclusion/exclusion criteria and experimental designs may influence observed treatment benefits. Methods: We conducted a systematic review and meta-analyses of TMS and tDCS treatment studies in PWA. Standard mean difference (SMD) for changes in picture naming accuracywas estimated; pooledSMDswere compared using a random-effects model. Results: Eight TMS (N= 143) and 8 tDCS studies (N= 140) met our inclusion criteria. Pooled SMDs of 0.448 (p < 0.001) in favor of TMS, and 0.395 (p < 0.001) in favor of tDCS were found. Between-subject designs were more common in subacute and within/crossover designs in chronic patients. TMS SMDs were significant in both chronic (SMD = 0.348) and subacute (SMD = 0.667) populations while those for tDCS were significant in chronic (SMD = 0.320) but not in subacute (SMD = 0.283) PWA. Conclusions: The magnitude of treatment effects appears to be consistent between TMS and tDCS in PWA. Larger-scale clinical trials should further substantiate our findings. [ABSTRACT FROM AUTHOR]

Background: Post-stroke loss and recovery of language functions evolves in time and space. A high functional dynamic can be observed in the first days and weeks after stroke, which has been associated with reorganisation processes in the left-lateralised language network, its right-hemisphere homologues and in the vicinity of the lesion site. With the advances in in vivo neuroimaging techniques, mapping changes in the language network over time (e.g., lesion extent, structural integrity of grey or white matter, task-based activity, functional or structural connectivity) is currently the focus of ongoing investigations. Main Contribution: This review highlights the recent findings on the neurobiology of language recovery from the hyperacute to the subacute phase after stroke. It relates pathophysiological processes of stroke evolution and the spatio-temporal characteristics of recovery patterns within the anatomically distributed language network to the behavioural dynamics of early language recovery. Conclusions: Understanding distinct, yet characteristic, recovery patterns within the language network promoting an improvement of language functions has lately provided new targets for non-invasive brain stimulation to enhance language rehabilitation mainly in the chronic phase after stroke. We argue that a more profound understanding of the natural history of behaviour–physiology relationships during aphasia evolution could open up new opportunities for an early system-level, neurobiologically motivated therapeutic use of neuromodulation techniques during language rehabilitation. [ABSTRACT FROM PUBLISHER]

Recovery from aphasia, loss of language following a cerebrovascular incident (stroke), is a complex process involving both left and right hemispheric regions. In our study, we analyzed the relationships between semantic processing behavioral data, lesion size and location, and percent signal change from functional magnetic resonance imaging (fMRI) data. This study included 14 persons with aphasia in the chronic stage of recovery (six or more months post stroke), along with normal controls, who performed semantic processing tasks of determining whether a written semantic feature matched a picture or whether two written words were related. Using region of interest (ROI) analysis, we found that left inferior frontal gyrus pars opercularis and pars triangularis, despite significant damage, were the only regions to correlate with behavioral accuracy. Additionally, bilateral frontal regions including superior frontal gyrus, middle frontal gyrus, and anterior cingulate appear to serve as an assistive network in the case of damage to traditional language regions that include inferior frontal gyrus, middle temporal gyrus, supramarginal gyrus, and angular gyrus. Right hemisphere posterior regions including right middle temporal gyrus, right supramarginal gyrus, and right angular gyrus are engaged in the case of extensive damage to left hemisphere language regions. Additionally, right inferior frontal gyrus pars orbitalis is presumed to serve a monitoring function. These results reinforce the importance of the left hemisphere in language processing in aphasia, and provide a framework for the relative importance of left and right language regions in the brain. [ABSTRACT FROM AUTHOR]

In the past few years, noninvasive cerebral stimulations have been used to modulate language task performance in healthy and aphasic patients. In this study, a dual transcranial direct current stimulation (tDCS) on anterior and posterior language areas was applied for 2 weeks to a patient with a possible crossed aphasia following a right hemisphere stroke. Inhibitory cathodal stimulation of the right Brodmann areas (BA) 44/45 and simultaneous anodal stimulation of the left BA 44/45 improved the patient’s performance in picture naming. Conversely, the same bilateral montage on BA 39/40 did not produce any significant improvement; finally, electrode polarity inversion over BA 39/40 yielded a further improvement compared with the first anterior stimulation. Our findings suggest that ipsilesional and contralesional areas could be useful in poststroke functional reorganization and provide new evidences for the therapeutic value of tDCS in aphasia. [ABSTRACT FROM AUTHOR]

In this study, we examined regions in the left and right hemisphere language network that were altered in terms of the underlying neural activation and effective connectivity subsequent to language rehabilitation. Eight persons with chronic post-stroke aphasia and eight normal controls participated in the current study. Patients received a 10 week semantic feature-based rehabilitation program to improve their skills. Therapy was provided on atypical examples of one trained category while two control categories were monitored; the categories were counterbalanced across patients. In each fMRI session, two experimental tasks were conducted: (a) picture naming and (b) semantic feature verification of trained and untrained categories. Analysis of treatment effect sizes revealed that all patients showed greater improvements on the trained category relative to untrained categories. Results from this study show remarkable patterns of consistency despite the inherent variability in lesion size and activation patterns across patients. Across patients, activation that emerged as a function of rehabilitation on the trained category included bilateral IFG, bilateral SFG, LMFG, and LPCG for picture naming; and bilateral IFG, bilateral MFG, LSFG, and bilateral MTG for semantic feature verification. Analysis of effective connectivity using Dynamic Causal Modeling (DCM) indicated that LIFG was the consistently significantly modulated region after rehabilitation across participants. These results indicate that language networks in patients with aphasia resemble normal language control networks and that this similarity is accentuated by rehabilitation. [ABSTRACT FROM AUTHOR]

Little is known about anatomical predictors of recovery from post-stroke aphasia. Forkel et al. use DTI of the perisylvian language networks to examine six-month recovery in patients with left-hemisphere stroke. Results reveal a role for the right-hemisphere language network in recovery, and may provide clinically useful predictive biomarkers.Stroke-induced aphasia is associated with adverse effects on quality of life and the ability to return to work. For patients and clinicians the possibility of relying on valid predictors of recovery is an important asset in the clinical management of stroke-related impairment. Age, level of education, type and severity of initial symptoms are established predictors of recovery. However, anatomical predictors are still poorly understood. In this prospective longitudinal study, we intended to assess anatomical predictors of recovery derived from diffusion tractography of the perisylvian language networks. Our study focused on the arcuate fasciculus, a language pathway composed of three segments connecting Wernicke’s to Broca’s region (i.e. long segment), Wernicke’s to Geschwind’s region (i.e. posterior segment) and Broca’s to Geschwind’s region (i.e. anterior segment). In our study we were particularly interested in understanding how lateralization of the arcuate fasciculus impacts on severity of symptoms and their recovery. Sixteen patients (10 males; mean age 60 ± 17 years, range 28–87 years) underwent post stroke language assessment with the Revised Western Aphasia Battery and neuroimaging scanning within a fortnight from symptoms onset. Language assessment was repeated at 6 months. Backward elimination analysis identified a subset of predictor variables (age, sex, lesion size) to be introduced to further regression analyses. A hierarchical regression was conducted with the longitudinal aphasia severity as the dependent variable. The first model included the subset of variables as previously defined. The second model additionally introduced the left and right arcuate fasciculus (separate analysis for each segment). Lesion size was identified as the only independent predictor of longitudinal aphasia severity in the left hemisphere [beta = −0.630, t(−3.129), P = 0.011]. For the right hemisphere, age [beta = −0.678, t(–3.087), P = 0.010] and volume of the long segment of the arcuate fasciculus [beta = 0.730, t(2.732), P = 0.020] were predictors of longitudinal aphasia severity. Adding the volume of the right long segment to the first-level model increased the overall predictive power of the model from 28% to 57% [F(1,11) = 7.46, P = 0.02]. These findings suggest that different predictors of recovery are at play in the left and right hemisphere. The right hemisphere language network seems to be important in aphasia recovery after left hemispheric stroke. [ABSTRACT FROM AUTHOR]

Purpose: Several studies have shown that transcranial direct current stimulation (tDCS) is a useful tool to enhance language recovery in aphasia. It has also been suggested that modulation of the neurotrophin brain-derived neurotrophic factor (BDNF) might be part of the mechanisms involved in tDCS effects on synaptic connectivity. However, all language studies have previously investigated the effects using unihemispheric stimulation. The purpose of the present study is to investigate the role of bihemispheric tDCS on language recovery and BDNF serum levels. Methods: Seven aphasic persons underwent an intensive language therapy in two different conditions: real bihemispheric stimulation over the left and right Broca's areas and a sham condition. Results: After the stimulation, patients exibited a significant recovery in three language tasks (picture description, noun and verb naming) compared to the sham condition which persisted in the follow-up session. No significant differences were found in BDNF serum levels after tDCS stimulation and in the follow-up session. However, a significant positive correlation was present for the real stimulation condition between percent changes in BDNF levels and in the verb naming task. Conclusions: The data suggest that this novel approach may potentiate the recovery of language in chronic aphasia. They also emphasize the importance to further investigate the role of possible biomarkers associated with tDCS treatment response in language recovery. [ABSTRACT FROM AUTHOR]

Highlights: [•] tDCS effects were investigated during a tongue twister repetition task. [•] Anodal tDCS increased response accuracy and speeded-up reaction times. [•] Cathodal tDCS reduced the performance in terms of accuracy and reaction times. [•] No significant differences were observed during the sham condition. [•] The left frontal region is critically involved in the process of speech repetition. [ABSTRACT FROM AUTHOR]

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Abstract: The goal of this paper is to discuss experimental design options available for establishing the effects of treatment in studies that aim to examine the neural mechanisms associated with treatment-induced language recovery in aphasia, using functional magnetic resonance imaging (fMRI). We present both group and single-subject experimental or case-series design options for doing this and address advantages and disadvantages of each. We also discuss general components of and requirements for treatment research studies, including operational definitions of variables, criteria for defining behavioral change and treatment efficacy, and reliability of measurement. Important considerations that are unique to neuroimaging-based treatment research are addressed, pertaining to the relation between the selected treatment approach and anticipated changes in language processes/functions and how such changes are hypothesized to map onto the brain. [Copyright &y& Elsevier]

Abstract: Functional magnetic resonance imaging is the most widely used imaging technique to study treatment-induced recovery in post-stroke aphasia. The longitudinal design of such studies adds to the challenges researchers face when studying patient populations with brain damage in cross-sectional settings. The present review focuses on issues specifically relevant to neuroimaging data analysis in aphasia treatment research identified in discussions among international researchers at the Neuroimaging in Aphasia Treatment Research Workshop held at Northwestern University (Evanston, Illinois, USA). In particular, we aim to provide the reader with a critical review of unique problems related to the pre-processing, statistical modeling and interpretation of such data sets. Despite the fact that data analysis procedures critically depend on specific design features of a given study, we aim to discuss and communicate a basic set of practical guidelines that should be applicable to a wide range of studies and useful as a reference for researchers pursuing this line of research. [Copyright &y& Elsevier]

Abstract: New structural and functional neuroimaging methods continue to rapidly develop, offering promising tools for cognitive neuroscientists. In the last 20years, advanced magnetic resonance imaging (MRI) techniques have provided invaluable insights into how language is represented and processed in the brain and how it can be disrupted by damage to, or dysfunction of, various parts of the brain. Current functional MRI (fMRI) approaches have also allowed researchers to purposefully investigate how individuals recover language after stroke. This paper presents recommendations for quantification of brain lesions derived from discussions among international researchers at the Neuroimaging in Aphasia Treatment Research Workshop held at Northwestern University (Evanston, Illinois, USA). Methods for detailing and characterizing the brain damage that can influence results of fMRI studies in chronic aphasic stroke patients are discussed. Moreover, we aimed to provide the reader with a set of general practical guidelines and references to facilitate choosing adequate structural imaging strategies that facilitate fMRI studies in aphasia treatment research. [Copyright &y& Elsevier]

Abstract: The design of functional neuroimaging studies investigating the neural changes that support treatment-based recovery of targeted language functions in acquired aphasia faces a number of challenges. In this paper, we discuss these challenges and focus on experimental tasks and experimental designs that can be used to address the challenges, facilitate the interpretation of results and promote integration of findings across studies. [Copyright &y& Elsevier]

Purpose: In aphasic patients, some studies have already emphasized the efficacy of transcranial direct current stimulation (tDCS) during the treatment of noun retrieval deficits. To date, in the same population, there are have been no studies addressing tDCS effects in the recovery of verb retrieval deficits. In this study, we wanted to test the potential of tDCS to improve verb production in a group of aphasic patients. Methods: Seven chronic subjects participated in an intensive language training for their difficulties in action naming. Each subject was treated with tDCS (20 min., 1 mA) over the left hemisphere in three different conditions: anodic tDCS over Wernicke's area, anodic tDCS and sham stimulation over Broca's area. Each experimental condition was performed in five consecutive daily sessions over three weeks with 6 days of intersession interval. Results: In all patients, results showed a significantly better response accuracy during the anodic tDCS over Broca's area with respect to the other two conditions which still persisted at one month after the end of the treatment suggesting a long-term effect on the recovery of their verb retrieval deficits. Conclusion: These findings further confirm that tDCS represents a useful new therapeutic interventions for the rehabilitation of lexical deficits in aphasic patients. [ABSTRACT FROM AUTHOR]