scholarly journals Cerebral Perfusion in Chronic Stroke: Implications for Lesion-Symptom Mapping and Functional MRI

2011 ◽  
Vol 24 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Jessica D. Richardson ◽  
Julie M. Baker ◽  
Paul S. Morgan ◽  
Chris Rorden ◽  
L. Bonilha ◽  
...  

Lesion-symptom mapping studies are based upon the assumption that behavioral impairments are directly related to structural brain damage. Given what is known about the relationship between perfusion deficits and impairment in acute stroke, attributing specific behavioral impairments to localized brain damage leaves much room for speculation, as impairments could also reflect abnormal neurovascular function in brain regions that appear structurally intact on traditional CT and MRI scans. Compared to acute stroke, the understanding of cerebral perfusion in chronic stroke is far less clear. Utilizing arterial spin labeling (ASL) MRI, we examined perfusion in 17 patients with chronic left hemisphere stroke. The results revealed a decrease in left hemisphere perfusion, primarily in peri-infarct tissue. There was also a strong relationship between increased infarct size and decreased perfusion. These findings have implications for lesion-symptom mapping studies as well as research that relies on functional MRI to study chronic stroke.

2019 ◽  
Author(s):  
Junhua Ding ◽  
Randi Martin ◽  
A. Cris Hamilton ◽  
Tatiana T. Schnur

AbstractHumans are uniquely able to retrieve and combine words into syntactic structure to produce connected speech. Previous identification of focal brain regions necessary for production focused primarily on associations with the content produced by speakers with chronic stroke, where function may have shifted to other regions after reorganization occurred. Here, we relate patterns of brain damage with deficits to the content and structure of spontaneous connected speech in 52 speakers during the acute stage of a left hemisphere stroke. Multivariate lesion behavior mapping demonstrated that damage to temporal-parietal regions impacted the ability to retrieve words and produce them within increasingly complex combinations. Damage primarily to inferior frontal cortex affected the production of syntactically accurate structure. In contrast to previous work, functional-anatomical dissociations did not depend on lesion size likely because acute lesions were smaller than typically found in chronic stroke. These results are consistent with predictions from theoretical models based primarily on evidence from language comprehension and highlight the importance of investigating individual differences in brain-language relationships in speakers with acute stroke.


Brain ◽  
2010 ◽  
Vol 133 (11) ◽  
pp. 3269-3280 ◽  
Author(s):  
Solène Kalénine ◽  
Laurel J. Buxbaum ◽  
Harry Branch Coslett

2019 ◽  
Author(s):  
Cortney M. Howard ◽  
Louisa L. Smith ◽  
H. Branch Coslett ◽  
Laurel J. Buxbaum

The mechanisms and brain regions underlying error monitoring in complex action are poorly understood, yet errors and impaired error correction in these tasks are hallmarks of apraxia, a common disorder associated with left hemisphere stroke. Accounts of monitoring of language posit an internal route by which production planning or competition between candidate representations provide predictive signals that monitoring is required to prevent error, and an external route in which output is monitored using the comprehension system. Abnormal reliance on the external route has been associated with damage to brain regions critical for sensory-motor transformation and a pattern of gradual error ‘clean-up’ called conduite d’approche (CD). Action pantomime data from 67 participants with left hemisphere stroke were consistent with versions of internal route theories positing that competition signals monitoring requirements. Support Vector Regression Lesion Symptom Mapping (SVR-LSM) showed that lesions in the inferior parietal, posterior temporal, and arcuate fasciculus/superior longitudinal fasciculus predicted action conduite d’approche, overlapping the regions previously observed in the language domain. A second experiment with 12 patients who produced substantial action CD assessed whether factors impacting the internal route (action production ability, competition) versus external route (vision of produced actions, action comprehension) influenced correction attempts. In these ‘high CD’ patients, vision of produced actions and integrity of gesture comprehension interacted to determine successful error correction, supporting external route theories. Viewed together, these and other data suggest that skilled actions are monitored both by an internal route in which conflict aids in detection and correction of errors during production planning, and an external route that detects mismatches between produced actions and stored knowledge of action appearance. The parallels between language and action monitoring mechanisms and neuroanatomical networks pave the way for further exploration of common and distinct processes across these domains.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Mark T Mackay ◽  
Jian Chen ◽  
Joseph Yang ◽  
Belinda Stojanovski ◽  
Sebastian Grunt ◽  
...  

Objectives: To investigate correlations between infarct topography on acute diffusion weighted MRI, using voxel-based lesion-symptom mapping (VLSM), and later development of cerebral palsy (CP) and neurological impairments, in neonatal arterial ischaemic stroke (AIS). Methods: Newborns were recruited from prospective Australian and Swiss pediatric stroke registries. CP diagnosis was based on clinical examination. Language or cognitive-behavioural impairments were assessed using the Pediatric Stroke Outcome Measure dichotomized to good (0-0.5) or poor (≥1), at ≥18 months of age. Infarcts were manually segmented using axial DWI images, and coregistered to the Melbourne Children’s Regional Infant Brain 2.0 atlas. All lesions were projected to the left hemisphere to obtain binary union masks. VLSM was conducted using MATLAB SPM12 toolbox. A generalised linear model was used to correlate the lesion mask with outcomes. Voxel-wise t test statistics were calculated, and corrected for multiple comparisons using family-wise error rate (FWE). Results: 85 newborns (55 male) met inclusion criteria. Infarct lateralization was left hemisphere in 62%, right in 8% and bilateral in 29%. At median age 2.1 years (IQR1.9-2.6), 34% developed CP and 42% had neurological impairments. 54 ROIs were correlated with CP (t>4.33; FWE <0.05); the 12 highest correlated ROIs were the superior corona radiata, putamen, anterior corona radiata, insula, thalamus, external capsule, pars triangularis, caudate, lateral orbitofrontal cortex, superior temporal cortex, pars opercularis and precentral cortex. (Figure) No significant correlations were found for poor language or cognitive-behavioural outcomes. Conclusions: Cerebral palsy following neonatal AIS correlates predominantly with regions of acute infarction directly involved in motor control, or in functionally connected regions. Brain regions associated with language or cognitive-behavioural impairment are less clear.


2021 ◽  
Author(s):  
Margaret Moore ◽  
Celine Gillebert ◽  
Nele Demeyere

Visuospatial neglect is a heterogenous syndrome which can occur following damage to either right or left hemisphere areas. This study employs voxel-lesion symptom mapping to identify the neural correlates of left and right egocentric and allocentric neglect in a large acute stroke cohort.A cohort of 446 acute stroke survivors (age = 26-95, 44% female) completed neuropsychological neglect assessment and routine clinical imaging. Similar to previous investigations, left egocentric and left allocentric neglect were associated with damage to distinct clusters of voxels within the posterior parietal and temporo-parietal junction areas. Unlike previous investigations, right egocentric neglect was found to most strongly associated with damage to more posterior voxels within left occipital cortical areas. Right allocentric neglect was found to be most strongly associated with damage to the anterior limb of the left internal capsule. Interestingly, the right hemisphere homologues of the areas implicated in right-lateralised neglect were not overlapping with those associated with left neglect impairment. This dissociation was present across both egocentric and allocentric neglect impairment. The results of this investigation suggest that right egocentric/allocentric neglect should not be characterised as a consequence of damage to left-hemisphere homologues of the right hemisphere attentional systems. These findings support the characterisation of visuospatial neglect as a heterogenous cluster of impairments rather than a unitary syndrome and provide novel insight into the neural correlates of spatial attention.


Brain ◽  
2020 ◽  
Vol 143 (3) ◽  
pp. 862-876
Author(s):  
Junhua Ding ◽  
Randi C Martin ◽  
A Cris Hamilton ◽  
Tatiana T Schnur

Abstract Humans are uniquely able to retrieve and combine words into syntactic structure to produce connected speech. Previous identification of focal brain regions necessary for production focused primarily on associations with the content produced by speakers with chronic stroke, where function may have shifted to other regions after reorganization occurred. Here, we relate patterns of brain damage with deficits to the content and structure of spontaneous connected speech in 52 speakers during the acute stage of a left hemisphere stroke. Multivariate lesion behaviour mapping demonstrated that damage to temporal-parietal regions impacted the ability to retrieve words and produce them within increasingly complex combinations. Damage primarily to inferior frontal cortex affected the production of syntactically accurate structure. In contrast to previous work, functional-anatomical dissociations did not depend on lesion size likely because acute lesions were smaller than typically found in chronic stroke. These results are consistent with predictions from theoretical models based primarily on evidence from language comprehension and highlight the importance of investigating individual differences in brain-language relationships in speakers with acute stroke.


2020 ◽  
Author(s):  
William Matchin ◽  
Alexandra Basilakos ◽  
Dirk-Bart den Ouden ◽  
Brielle C. Stark ◽  
Gregory Hickok ◽  
...  

AbstractIn the early and mid 1800s, scientists debated whether the human brain was functionally differentiated with respect to cognition. The issue was largely resolved when specific language impairments were identified following focal patterns of brain damage. However, neuroimaging has revived this discussion, as many studies find similar syntactic and semantic effects across the set of brain regions implicated in language. Here we address this modern debate using lesion-symptom mapping in two large, partially-overlapping groups of people with left hemisphere brain damage due to stroke (N=121, N=92). We identified multiple measure by region interaction effects, associating damage to the posterior middle temporal gyrus with syntactic comprehension deficits, damage to posterior inferior frontal gyrus with expressive agrammatism, and damage to inferior angular gyrus with semantic category word fluency deficits. Our results are inconsistent with recent hypotheses that regions of the language network play similar roles in high-level linguistic processing.


Author(s):  
Caroline Malherbe ◽  
Bastian Cheng ◽  
Alina Königsberg ◽  
Tae-Hee Cho ◽  
Martin Ebinger ◽  
...  

Abstract Lesion analysis is a fundamental and classical approach for inferring the causal contributions of brain regions to brain function. However, many studies have been limited by shortcomings of methodology or clinical data. Aiming to overcome these limitations, we here use an objective multivariate approach based on game theory, Multi-perturbation Shapley value Analysis, in conjunction with data from a large cohort of 394 acute stroke patients, to derive causal contributions of brain regions to four principal functional components of the widely used National Institutes of Health Stroke Score measure. The analysis was based on a high-resolution parcellation of the brain into 294 gray and white matter regions. Through initial lesion symptom mapping for identifying all potential candidate regions and repeated iterations of the game-theoretical approach to remove non-significant contributions, the analysis derived the smallest sets of regions contributing to each of the four principal functional components as well as functional interactions among the regions. Specifically, the factor “language and consciousness” was related to contributions of cortical regions in the left hemisphere, including the prefrontal gyrus, the middle frontal gyrus, the ventromedial putamen, and the inferior frontal gyrus. Right and left motor functions were associated with contributions of the left and right dorsolateral putamen and the posterior limb of the internal capsule, correspondingly. Moreover, the superior corona radiata and the paracentral lobe of the right hemisphere as well as the right caudal area 23 of the cingulate gyrus were mainly related to left motor function, while the prefrontal gyrus, the external capsule and the sagittal stratum fasciculi of the left hemisphere contributed to right motor function. Our approach demonstrates a practically feasible strategy for applying an objective lesion inference method to a high-resolution map of the human brain and distilling a small, characteristic set of gray and white matter structures contributing to fundamental brain functions. In addition, we present novel findings of synergistic interactions between brain regions that provide insight into the functional organisation of brain networks.


2020 ◽  
Vol 31 (2) ◽  
pp. 62-68
Author(s):  
Sara E. Holm ◽  
Alexander Schmidt ◽  
Christoph J. Ploner

Abstract. Some people, although they are perfectly healthy and happy, cannot enjoy music. These individuals have musical anhedonia, a condition which can be congenital or may occur after focal brain damage. To date, only a few cases of acquired musical anhedonia have been reported in the literature with lesions of the temporo-parietal cortex being particularly important. Even less literature exists on congenital musical anhedonia, in which impaired connectivity of temporal brain regions with the Nucleus accumbens is implicated. Nonetheless, there is no precise information on the prevalence, causes or exact localization of both congenital and acquired musical anhedonia. However, the frequent involvement of temporo-parietal brain regions in neurological disorders such as stroke suggest the possibility of a high prevalence of this disorder, which leads to a considerable reduction in the quality of life.


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