Recovery from aphasia in the first year after stroke

Brain, Journal Year: 2022, Volume and Issue: 146(3), P. 1021 - 1039

Published: April 7, 2022

Most individuals who experience aphasia after a stroke recover to some extent, with the majority of gains taking place in first year. The nature and time course this recovery process is only partially understood, especially its dependence on lesion location which are most important determinants outcome. aim study was provide comprehensive description patterns from year stroke. We recruited 334 patients acute left hemisphere supratentorial ischaemic or haemorrhagic evaluated their speech language function within 5 days using Quick Aphasia Battery (QAB). At initial point, 218 presented aphasia. Individuals were followed longitudinally, follow-up evaluations at 1 month, 3 months, post-stroke, wherever possible. Lesions manually delineated based clinical MRI CT imaging. Patients without divided into 13 groups similar, commonly occurring brain damage. Trajectories then investigated as group (i.e. extent) speech/language domain (overall function, word comprehension, sentence finding, grammatical construction, phonological encoding, motor programming, execution, reading). found that dynamic, multidimensional, gradated, little explanatory role for subtypes binary concepts such fluency. circumscribed frontal lesions recovered well, consistent previous observations. More surprisingly, larger extending parietal temporal lobes also did relatively temporal, temporoparietal, lesions. Persistent moderate severe deficits common extensive damage throughout middle cerebral artery distribution temporoparietal There striking differences between domains rates relationships overall suggesting specific differ extent they redundantly represented network, opposed depending specialized cortical substrates. Our findings have an immediate application will enable clinicians estimate likely individual patients, well uncertainty these predictions, acutely observable neurological factors.

Language: Английский

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The language network as a natural kind within the broader landscape of the human brain

Nature reviews. Neuroscience, Journal Year: 2024, Volume and Issue: 25(5), P. 289 - 312

Published: April 12, 2024

Language: Английский

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Language and developmental plasticity after perinatal stroke

Proceedings of the National Academy of Sciences, Journal Year: 2022, Volume and Issue: 119(42)

Published: Oct. 10, 2022

The mature human brain is lateralized for language, with the left hemisphere (LH) primarily responsible sentence processing and right (RH) suprasegmental aspects of language such as vocal emotion. However, it has long been hypothesized that in early life there plasticity allowing young children to acquire other cortical regions when LH areas are damaged. If true, what constraints on functional reorganization? Which can happens functions these ordinarily perform? We address questions by examining long-term outcomes adolescents adults who, infants, had a perinatal arterial ischemic stroke subserving processing. compared them their healthy age-matched siblings. All participants were tested battery behavioral imaging tasks. While impaired some nonlinguistic cognitive abilities, sentences emotion was normal equal In almost all, abilities have both developed RH. Our results provide insights into remarkable ability reorganize language. Reorganization highly constrained, always RH frontotemporal homotopic location brain. This activation somewhat segregated from processing, suggesting two perform best each its own neural territory.

Language: Английский

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Disentangling neuroplasticity mechanisms in post-stroke language recovery

Brain and Language, Journal Year: 2024, Volume and Issue: 251, P. 105381 - 105381

Published: Feb. 24, 2024

A major objective in post-stroke aphasia research is to gain a deeper understanding of neuroplastic mechanisms that drive language recovery, with the ultimate goal enhancing treatment outcomes. Subsequent recent advances neuroimaging techniques, we now have ability examine more closely how neural activity patterns change after stroke. However, way these changes relate impairments and recovery still debated. The aim this review provide theoretical framework better investigate interpret neuroplasticity underlying aphasia. We detail two sets observed at synaptic level may explain functional findings network level: feedback-based homeostatic plasticity associative Hebbian plasticity. In conjunction mechanisms, higher-order cognitive control processes dynamically modulate other regions meet communication demands, despite reduced resources. This work provides network-level neurobiological for can be used define guidelines personalized development.

Language: Английский

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Functional characterization of the language network of polyglots and hyperpolyglots with precision fMRI

Cerebral Cortex, Journal Year: 2024, Volume and Issue: 34(3)

Published: March 1, 2024

Abstract How do polyglots—individuals who speak five or more languages—process their languages, and what can this population tell us about the language system? Using fMRI, we identified network in each of 34 polyglots (including 16 hyperpolyglots with knowledge 10+ languages) examined its response to native language, non-native languages varying proficiency, unfamiliar languages. All conditions engaged all areas relative a control condition. Languages that participants rated as higher proficiency elicited stronger responses, except for which similar lower than proficiency. Furthermore, were typologically related participants’ high-to-moderate-proficiency unrelated The results suggest network’s magnitude scales degree engagement linguistic computations (e.g. lexical access syntactic-structure building). We also replicated prior finding weaker responses non-polyglot bilinguals. These contribute our understanding how multiple coexist within single brain provide new evidence responds strongly stimuli fully engage computations.

Language: Английский

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Demystifying the Complexity of Aphasia Treatment: Application of the Rehabilitation Treatment Specification Systemx

Archives of Physical Medicine and Rehabilitation, Journal Year: 2021, Volume and Issue: 103(3), P. 574 - 580

Published: Nov. 5, 2021

Language: Английский

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Functional differentiation in the language network revealed by lesion-symptom mapping

NeuroImage, Journal Year: 2021, Volume and Issue: 247, P. 118778 - 118778

Published: Dec. 9, 2021

Theories of language organization in the brain commonly posit that different regions underlie distinct linguistic mechanisms. However, such theories have been criticized on grounds many neuroimaging studies processing find similar effects across regions. Moreover, condition by region interaction effects, which provide strongest evidence functional differentiation between regions, rarely offered support these theories. Here we address this using lesion-symptom mapping three large, partially-overlapping groups aphasia patients with left hemisphere damage due to stroke (N = 121, N 92, 218). We identified multiple measure associating posterior middle temporal gyrus syntactic comprehension deficits, inferior frontal expressive agrammatism, and angular semantic category word fluency deficits. Our results are inconsistent recent hypotheses network undifferentiated respect high-level processing.

Language: Английский

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Predictors of Therapy Response in Chronic Aphasia: Building a Foundation for Personalized Aphasia Therapy

Journal of Stroke, Journal Year: 2022, Volume and Issue: 24(2), P. 189 - 206

Published: May 31, 2022

Chronic aphasia, a devastating impairment of language, affects up to third stroke survivors. Speech and language therapy has consistently been shown improve function in prior clinical trials, but few clinicially applicable predictors individual response have identified date. Consequently, clinicians struggle substantially with prognostication the management aphasia. A rising prevalence particular younger populations, emphasized increasing demand for personalized approach aphasia therapy, that is, aimed at maximizing recovery each reference evidence-based recommendations. In this narrative review, we discuss current state literature respect commonly studied particular, focus our discussion on biographical, neuropsychological, neurobiological predictors, emphasize limitations literature, summarize consistent findings, consider how research field can better support development therapy. conclusion, review indicates future efforts should aim recruit larger samples people including by establishing multisite centers.

Language: Английский

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The Wernicke conundrum revisited: evidence from connectome-based lesion-symptom mapping

Brain, Journal Year: 2022, Volume and Issue: 145(11), P. 3916 - 3930

Published: June 21, 2022

Abstract Wernicke’s area has been assumed since the 1800s to be primary region supporting word and sentence comprehension. However, in 2015 2019, Mesulam colleagues raised what they termed ‘Wernicke conundrum’, noting widespread variability anatomical definition of this presenting data from progressive aphasia that challenged classical assumption. To resolve conundrum, posited a ‘double disconnection’ hypothesis: comprehension deficits stroke-based result disconnection anterior temporal inferior frontal regions other parts brain due white matter damage, rather than dysfunction itself. test hypothesis, we performed lesion-deficit correlations, including connectome-based lesion-symptom mapping, four large, partially overlapping groups English-speaking chronic left hemisphere stroke survivors. After removing variance object recognition associative semantic processing, same middle posterior lobe were implicated both complex non-canonical deficits. Connectome mapping revealed similar temporal-occipital disconnections for impaired comprehension, pole. We found an additional significant temporal-parietal deficits, which may indicate role phonological working memory processing syntax, but no disconnections. Moreover, damage these middle-posterior was associated with even when accounting strongest disconnections, respectively. Our results largely agree notion area, defined here as superior gyrus sulcus, supports suggest pole speak against hypothesis double disconnection.

Language: Английский

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Remapping and Reconnecting the Language Network after Stroke

Brain Sciences, Journal Year: 2024, Volume and Issue: 14(5), P. 419 - 419

Published: April 24, 2024

Here, we review the literature on neurotypical individuals and with post-stroke aphasia showing that right-hemisphere regions homologous to language network other regions, like right cerebellum, are activated in tasks support even healthy people. We propose recovery occurs largely by potentiating hemisphere networks previously supported a lesser degree modulating connection strength between nodes of undamaged left-hemisphere network. Based this premise (supported evidence review), interventions should be aimed at through Hebbian learning or augmenting connections neuroplasticity, such as non-invasive brain stimulation perhaps modulation neurotransmitters involved neuroplasticity. treatment studies have taken approach. conclude further rehabilitation aim is justified.

Language: Английский

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