Brain Structure and Function, Год журнала: 2022, Номер 227(9), С. 3173 - 3187
Опубликована: Июль 26, 2022
Язык: Английский
Brain, Год журнала: 2020, Номер 143(3), С. 844 - 861
Опубликована: Янв. 21, 2020
Abstract The loss and recovery of language functions are still incompletely understood. This longitudinal functional MRI study investigated the neural mechanisms underlying in patients with post-stroke aphasia putting particular emphasis on impact lesion site. To identify patterns language-related activation, an auditory sentence comprehension paradigm was administered to circumscribed lesions either left frontal (n = 17) or temporo-parietal cortex. Patients were examined repeatedly during acute (≤1 week, t1), subacute (1–2 weeks, t2) chronic phase (>6 months, t3) post-stroke; healthy age-matched control subjects tested once. separation into two patient groups allowed for a direct comparison contributions distinct lesion-dependent network components reorganization between both groups. We hypothesized that activation hemisphere spared perilesional cortex as well lesion-homologue right varies across time. In addition, we expected domain-general networks serving cognitive independently contribute recovery. First, found global disturbance is characterized by reduced including areas distant (i.e. diaschisis) subsequent reactivation resolution diaschisis). These phenomena driven lesions. Second, identified lesion-independent sequential pattern increased activity bilateral followed temporal phase. Third, observed involvement only but not Fourth, irrespective location, predominantly occurred pre-existing showing comparable controls. Finally, detected different relationships performance demonstrating relevance Our findings highlight dynamics clearly depend location hence open new perspectives neurobiologically motivated strategies rehabilitation, such individually-tailored targeted application neuro-stimulation.
Язык: Английский
Процитировано
133
Brain, Год журнала: 2020, Номер 143(5), С. 1525 - 1540
Опубликована: Март 14, 2020
Abstract Acute ischaemic stroke disturbs healthy brain organization, prompting subsequent plasticity and reorganization to compensate for the loss of specialized neural tissue function. Static resting state functional MRI studies have already furthered our understanding cerebral by estimating stroke-induced changes in network connectivity aggregated over duration several minutes. In this study, we used dynamic analyses increase temporal resolution seconds explore transient configurations motor acute stroke. To end, collected data 31 patients with 17 age-matched control subjects. Stroke presented moderate severe hand deficits. By within a sliding window framework, identified three distinct motor-related networks. Motor networks were organized into regional domains, i.e. cortical, subcortical cerebellar domain. The patterns diverged from those controls depending on severity initial impairment. Moderately affected (n = 18) spent significantly more time weakly connected configuration that was characterized low levels connectivity, both locally as well between distant regions. contrast, severely 13) showed significant preference transitions spatially segregated configuration. This featured particularly high local domains anti-correlated across domains. A third represented an intermediate pattern compared preceding two, predominantly encompassed decreased interhemispheric cortical independent individual deficit severity. Alterations thus closely resembled previously reported ones originating static post-stroke. summary, not only prompted networks, but it also caused characteristic properties large-scale interactions deficit. These findings offer new vistas mechanisms underlying neurological symptoms, treatment effects patients.
Язык: Английский
Процитировано
103
Cortex, Год журнала: 2018, Номер 107, С. 229 - 237
Опубликована: Янв. 2, 2018
Traditional neuropsychological approaches emphasize the specificity of behavioral deficits and modular organization brain. At population level, however, there is emerging evidence that are correlated resulting in a low dimensional structure post-stroke neurological impairments. Here we consider implications dimensionality for three-way mapping between structural damage, altered physiology, deficits. Understanding this will be aided by large-sample studies apply multivariate models focus on explained percentage variance, as opposed to univariate lesion-symptom techniques report statistical significance. The following stroke paralleled widespread, yet relatively consistent, changes functional connectivity (FC), including reduction modularity. Both related damage white matter subcortical grey commonly produced stroke. We suggest large-scale physiological abnormalities reduce variety neural states visited during task processing at rest, limited repertoire states.
Язык: Английский
Процитировано
90
Neurobiology of Language, Год журнала: 2020, Номер 2(1), С. 22 - 82
Опубликована: Сен. 23, 2020
Recovery from aphasia is thought to depend on neural plasticity, that is, functional reorganization of surviving brain regions such they take new or expanded roles in language processing. We carried out a systematic review and meta-analysis all articles published between 1995 early 2020 have described imaging studies six more individuals with post-stroke aphasia, reported analyses bearing neuroplasticity Each study was characterized appraised detail, particular attention three critically important methodological issues: task performance confounds, contrast validity, correction for multiple comparisons. identified 86 describing total 561 relevant analyses. found limitations related comparisons been pervasive. Only few claims about processing are strongly supported by the extant literature: first, left hemisphere less activated than neurologically normal controls, second, cohorts activity regions, possibly temporal lobe region right hemisphere, positively correlated function. There modest, equivocal evidence claim differentially recruit homotopic but no compelling differential recruitment additional domain-general networks. modest return function over time, longitudinal dynamic network.
Язык: Английский
Процитировано
78
Journal of Neurology Neurosurgery & Psychiatry, Год журнала: 2019, Номер 90(10), С. 1147 - 1155
Опубликована: Май 4, 2019
Given the profound impact of language impairment after stroke (aphasia), neuroplasticity research is garnering considerable attention as means for eventually improving aphasia treatments and how they are delivered. Functional structural neuroimaging studies indicate that can recruit both residual new neural mechanisms to improve function modalities may hold promise in predicting treatment outcome. In relatively small clinical trials, non-invasive brain stimulation behavioural manipulations targeting activation or suppression specific cortices outcomes. Recent interventions employ principles consistent with inducing also showing improved performance trained novel items contexts. While knowledge rapidly accumulating, larger trials emphasising select optimal paradigms individualised needed. Finally, a model incorporate growing into practice could help focus future research.
Язык: Английский
Процитировано
77
Neuropharmacology, Год журнала: 2022, Номер 226, С. 109398 - 109398
Опубликована: Дек. 27, 2022
This theoretical article revives a classical bridging construct, canalization, to describe new model of general factor psychopathology. To achieve this, we have distinguished between two types plasticity, an early one that call 'TEMP' for 'Temperature or Entropy Mediated Plasticity', and another, 'canalization', which is close Hebbian plasticity. These forms plasticity can be most easily by their relationship 'precision' inverse variance; TEMP relates increased variance decreased precision, whereas the opposite true canalization. also subsumes learning rate, (Ising) temperature entropy. Dictionary definitions 'plasticity' it as property being shaped molded; better match this. Importantly, propose 'pathological' phenotypes develop via mechanisms canalization defensive response adversity associated distress dysphoria. Our states entrenches in psychopathology, narrowing phenotypic state-space agent develops expertise pathology. We suggest - combined with gently guiding psychological support counter address questions whether when adaptive versus maladaptive, furnish our references basic human neuroscience, offer concrete experiments measures test its main hypotheses implications. part Special Issue on "National Institutes Health Psilocybin Research Speaker Series".
Язык: Английский
Процитировано
68
Nature Communications, Год журнала: 2022, Номер 13(1)
Опубликована: Авг. 29, 2022
The mechanisms controlling dynamical patterns in spontaneous brain activity are poorly understood. Here, we provide evidence that cortical dynamics the ultra-slow frequency range (<0.01-0.1 Hz) requires intact cortical-subcortical communication. Using functional magnetic resonance imaging (fMRI) at rest, identify Dynamic Functional States (DFSs), transient but recurrent clusters of and subcortical regions synchronizing frequencies. We observe shifts temporally coincident with clusters, flexibly either limbic (hippocampus/amygdala), or nuclei (thalamus/basal ganglia). Focal lesions induced by stroke, especially those damaging white matter connections between basal ganglia/thalamus cortex, provoke anomalies fraction times, dwell transitions DFSs, causing a bias toward abnormal network integration. Dynamical observed 2 weeks after stroke recover time contribute to explaining neurological impairment long-term outcome.
Язык: Английский
Процитировано
45
Nature Communications, Год журнала: 2022, Номер 13(1)
Опубликована: Июнь 27, 2022
Abstract The critical brain hypothesis states that biological neuronal networks, because of their structural and functional architecture, work near phase transitions for optimal response to internal external inputs. Criticality thus provides function behavioral capabilities. We test this by examining the influence injury (strokes) on criticality neural dynamics estimated at level single participants using directly measured individual connectomes whole-brain models. Lesions engender a sub-critical state recovers over time in parallel with behavior. improvement is associated re-modeling specific white-matter connections. show personalized dynamical models poised track dynamics, alteration post-stroke, behavior participants.
Язык: Английский
Процитировано
43
Trends in Neurosciences, Год журнала: 2024, Номер 47(4), С. 303 - 318
Опубликована: Фев. 23, 2024
Stroke is a leading cause of adult disability. Understanding stroke damage and recovery requires deciphering changes in complex brain networks across different spatiotemporal scales. While recent developments readout technologies progress network modeling have revolutionized current understanding the effects on at macroscale, reorganization smaller scale remains incompletely understood. In this review, we use conceptual framework graph theory to define from nano- macroscales. Highlighting stroke-related connectivity studies multiple scales, argue that multiscale connectomics-based approaches may provide new routes better evaluate structural functional remapping after during recovery.
Язык: Английский
Процитировано
10
Brain and Language, Год журнала: 2024, Номер 251, С. 105381 - 105381
Опубликована: Фев. 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.
Язык: Английский
Процитировано
10