Several mechanisms have been attributed to post-stroke loss and recovery of language functions. However, the significance and timing of domain-general and homotopic right-hemispheric activation is controversial. We aimed to examine the effect of left-hemispheric lesion location and time post-stroke on right-hemispheric activation. Voxel-based lesion analyses were informed by auditory language-related fMRI activation of 71 patients with left middle cerebral artery stroke examined longitudinally in the acute, subacute and early chronic phase. Language activation was determined in several right-hemispheric regions of interest and served as regressor of interest for voxel-based lesion analyses. We found that an acute to chronic increase of language activation in the right supplementary motor area was associated with lesions to the left extreme capsule as part of the ventral language pathway. Importantly, this activation increase correlated significantly with improvement of out-of-scanner comprehension abilities. We interpret our findings in terms of successful domain-general compensation in patients with critical left frontotemporal disconnection due to damage to the ventral language pathway but relatively spared cortical language areas.
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http://dx.doi.org/10.1016/j.nicl.2022.103169 | DOI Listing |
Brain Commun
December 2024
Medical Research Council (MRC) Cognition and Brain Sciences Unit, University of Cambridge, Cambridge CB2 7EF, UK.
We investigated semantic cognition in the logopenic variant of primary progressive aphasia, including (i) the status of verbal and non-verbal semantic performance; and (ii) whether the semantic deficit reflects impaired semantic control. Our hypothesis that individuals with logopenic variant of primary progressive aphasia would exhibit semantic control impairments was motivated by the anatomical overlap between the temporoparietal atrophy typically associated with logopenic variant of primary progressive aphasia and lesions associated with post-stroke semantic aphasia and Wernicke's aphasia, which cause heteromodal semantic control impairments. We addressed the presence, type (semantic representation and semantic control; verbal and non-verbal), and progression of semantic deficits in logopenic variant of primary progressive aphasia.
View Article and Find Full Text PDFJ Neurosci
January 2025
Wellcome Centre for Integrative Neuroimaging; Nuffield Department of Clinical Neuroscience, University of Oxford.
Damage to the primary visual cortex (V1) results in visual field deficits on the contralateral side of the world corresponding to the damaged region. Patients with such loss nonetheless show varying residual vision within this apparently blind region, with the neural mechanisms underlying this ability obscured by small study populations. We identified lesions on structural scans from 39 patients (12 female) with hemianopia and occipital lobe damage.
View Article and Find Full Text PDFBrain Sci
December 2024
Neuroinformatics Laboratory (NiLab), Bruno Kessler Foundation (FBK), 39123 Trento, Italy.
In glioma surgery, maximizing the extent of resection while preserving cognitive functions requires an understanding of the unique architecture of the white matter (WM) pathways of the single patient and of their spatial relationship with the tumor. Tractography enables the reconstruction of WM pathways, and bundle segmentation allows the identification of critical connections for functional preservation. This study evaluates the effectiveness of a streamline-based approach for bundle segmentation on a clinical dataset as compared to the traditional ROI-based approach.
View Article and Find Full Text PDFBrain Commun
December 2024
Department of Communication Sciences and Disorders, University of South Carolina, Columbia, SC 29208, USA.
Syntactic processing and verbal working memory are both essential components to sentence comprehension. Nonetheless, the separability of these systems in the brain remains unclear. To address this issue, we performed causal-inference analyses based on lesion and connectome network mapping using MRI and behavioural testing in two groups of individuals with chronic post-stroke aphasia.
View Article and Find Full Text PDFEur Radiol
December 2024
Department of Neurosurgery, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China.
Background: This study aimed to establish a voxel-based map to predict the occurrence of cerebellar mutism syndrome (CMS) and investigate the relationship between CMS and motor dysfunction.
Method: This multicenter study cohort included 224 patients diagnosed with medulloblastoma at Beijing Children's Hospital (n = 88) and Beijing Tiantan Hospital (n = 136). The dataset was randomly divided into training (n = 95), test (n = 41), and validation (n = 88) datasets.
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