scholarly journals Dissociation between frontal and temporal-parietal contributions to connected speech in acute stroke

Brain ◽  
2020 ◽  
Vol 143 (3) ◽  
pp. 862-876
Author(s):  
Junhua Ding ◽  
Randi C Martin ◽  
A Cris Hamilton ◽  
Tatiana T Schnur
Keyword(s):  
Acute Stroke ◽  
Syntactic Structure ◽  
Theoretical Models ◽  
Brain Regions ◽  
Lesion Size ◽  
Acute Stage ◽  
Chronic Stroke ◽  
Connected Speech ◽  
Left Hemisphere Stroke ◽  
Previous Identification

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.

scholarly journals Dissociation between Frontal and Temporal-Parietal Contributions to Connected Speech in Acute Stroke

2019 ◽  
Author(s):  
Junhua Ding ◽  
Randi Martin ◽  
A. Cris Hamilton ◽  
Tatiana T. Schnur
Keyword(s):  
Acute Stroke ◽  
Syntactic Structure ◽  
Theoretical Models ◽  
Brain Regions ◽  
Lesion Size ◽  
Acute Stage ◽  
Chronic Stroke ◽  
Connected Speech ◽  
Left Hemisphere Stroke ◽  
Previous Identification

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.

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 ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Functional Mri ◽  
Brain Damage ◽  
Left Hemisphere ◽  
Cerebral Perfusion ◽  
Strong Relationship ◽  
Brain Regions ◽  
Chronic Stroke ◽  
Behavioral Impairments ◽  
Lesion Symptom Mapping

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.

The Social Neuroscience of Cooperation

2018 ◽  
Author(s):  
Jay Joseph Van Bavel
Keyword(s):  
Theoretical Models ◽  
Brain Regions ◽  
Review Literature ◽  
Social Neuroscience ◽  
Future Research ◽  
A Value ◽  
Group Cooperation ◽  
Neural Processes ◽  
The Social ◽  
Cooperative Decision Making

We review literature from several fields to describe common experimental tasks used to measure human cooperation as well as the theoretical models that have been used to characterize cooperative decision-making, as well as brain regions implicated in cooperation. Building on work in neuroeconomics, we suggest a value-based account may provide the most powerful understanding the psychology and neuroscience of group cooperation. We also review the role of individual differences and social context in shaping the mental processes that underlie cooperation and consider gaps in the literature and potential directions for future research on the social neuroscience of cooperation. We suggest that this multi-level approach provides a more comprehensive understanding of the mental and neural processes that underlie the decision to cooperate with others.

scholarly journals Physiological parameters deterioration in acute stage after stroke: Rehabilitation versus conventional care

2019 ◽  
Vol 10 (3) ◽  
pp. 79
Author(s):  
Reham AbdElhamed AbdElmawla Elsaid ◽  
Amina Mohamed AbdElfatah Sliman
Keyword(s):  
Acute Stroke ◽  
Acute Phase ◽  
Stroke Rehabilitation ◽  
Recovery Period ◽  
Acute Stage ◽  
Conventional Care ◽  
Physiological Parameters ◽  
Stroke Recovery ◽  
University Hospital ◽  
Control Group

Objective: Stroke is considered the main health problem and the second leading cause of death worldwide. Stroke resulting in varied and unpredictable complications if not managed correctly in the acute stage with intensive rehabilitation therapy which may affect stroke prognosis, and resulting functional decline. Therefore, the aim of the study was to explore the consequences of rehabilitation versus conventional care on physiological parameters during the acute stroke recovery period.Methods: The quasi-experimental research design was used in the neurology department at Mansoura University Hospital. A convenient sample of sixty-four adult patients of both sex with stroke, who corresponded to inclusion criteria was assigned into two equal groups, study group (rehabilitation group) and control group (conventional care).Results: The results indicates, acute phase rehabilitation limit physiological parameters deterioration during acute stroke recovery period comparing to conventional care only.Conclusions: Acute phase stroke rehabilitation has a significant positive impact on physiological parameters.

scholarly journals Corpus callosal microstructure predicts bimanual motor performance in chronic stroke survivors

2021 ◽  
Author(s):  
Rini Varghese ◽  
Brianna Chang ◽  
Bokkyu Kim ◽  
Sook-Lei Liew ◽  
Nicolas Schweighofer ◽  
...  
Keyword(s):  
Structural Damage ◽  
Diffusion Tensor ◽  
Lesion Size ◽  
Chronic Stroke ◽  
Stroke Survivors ◽  
Bimanual Performance ◽  
Paretic Limb ◽  
Bimanual Task ◽  
Effect Of Age ◽  
Bimanual Tasks

Much of the research using diffusion tensor imaging (DTI) in stroke focuses on characterizing the microstructural status of corticospinal tracts and its utility as a prognostic biomarker. However, the ischemic event in the lesioned cortex also triggers structural and functional alterations in its contralateral homolog through the corpus callosum (CC), known as transcallosal diaschisis. The few studies that have characterized the microstructural status of the CC using DTI only examine its relationship with paretic limb performance. Given the well-established role of the CC for bimanual coordination, especially fibers connecting the larger sensorimotor networks such as prefrontal, premotor and supplementary motor regions, we examine the relationship between the microstructural status of the CC and bimanual performance in chronic stroke survivors (n = 41). We used movement times for two self-initiated and self-paced bimanual tasks to capture bimanual performance. Using publicly available control datasets (n = 52), matched closely for acquisition parameters, including sequence, diffusion gradient strength and number of directions, we also explored the effect of age and stroke on callosal microstructure. We found that callosal microstructure was significantly associated with bimanual performance in chronic stroke survivors such that those with lower callosal FA were slower at completing the bimanual task. Notably, while the primary sensorimotor regions (CC3) showed the strongest relationship with bimanual performance, this was closely followed by the premotor/supplementary motor (CC2) and the prefrontal (CC1) regions. We used multiple mixed regression to systematically account for loss of callosal axons (i.e., normalized callosal volume) as well as differences in lesion size and other metrics of structural damage. Chronic stroke survivors presented with significantly greater loss of callosal fiber orientation (lower mean FA) compared to neurologically intact, age-similar controls, who in turn presented with lower callosal FA compared to younger controls. The effect of age and stroke were observed for all regions of the CC except the splenium. These preliminary findings suggest that in chronic stroke survivors with relatively localized lesions, callosal microstructure can be expected to change beyond the primary sensorimotor regions and might impact coordinated performance of self-initiated and cooperative bimanual tasks.

Does Hyperglycaemia Result in Larger Lesion Size in Acute Stroke?

1994 ◽  
Vol 23 (suppl 1) ◽  
pp. P4-P4
Author(s):  
F. Tracey ◽  
V.L.S Crawford ◽  
J.T. Lawson ◽  
R.W. Stout
Keyword(s):  
Acute Stroke ◽  
Lesion Size

Abstract 2856: Lesion load of Corticospinal Tract and Initial Motor Impairment in the Acute Stroke Phase Predict Motor Impairment 3 Months Post-Stroke

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Wuwei Feng ◽  
Jing Wang ◽  
Evgeny Sidorov ◽  
Christine Holmstedt ◽  
Christopher Doughty ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Stroke ◽  
Corticospinal Tract ◽  
Motor Impairment ◽  
Lesion Size ◽  
Sectional Area ◽  
Lesion Load ◽  
Cross Sectional ◽  
Post Stroke ◽  
Days Of Therapy

Background: We use lesion-mapping techniques in combination with diffusion tensor imaging to quantitatively test the hypothesis that motor impairment 3 months post- stroke is inversely related to the lesion load of the corticospinal tract (CST) in the acute stroke phase. Methods: We prospectively followed up a cohort of 32 patients who presented with their first-ever acute ischemic stroke with various degree of motor deficit , had a MRI during the hospitalization, and had follow-up motor assessments using the Fugl-Meyer Upper Extremity Scale (FM-UE) at 3 months (+/- 2 weeks) after stroke. We calculated a CST-lesion load for each patient by overlaying the patient’s lesion map from diffusion weighted image with a probabilistic DTI tract constructed from 12 age-matched healthy subjects . Both raw and weighted (which accounts for the narrowing of the CST as it descends from the motor cortex to the posterior limb of the internal capsule) were calculated; weighted lesion-loads were calculated by multiplying the lesion-tract overlap on each slice by the ratio of the maximum cross-sectional area of the tract to the cross-sectional area of the tract on that particular slice). A multiple regression is fit to assess the predicted value of CST lesion load (raw or weighted), along with other variables such age, gender, lesion size, initial impairment, days of therapy known to have an possible effect on motor outcome. Results: CST-lesion load and initial motor impairment are found to be significant predictors of upper extremity motor impairment at 3 months post-stroke. Age, gender, lesion size or days of therapy does not have predictive value in our cohort study. The adjusted R² is 0.63 with initial impairment and raw lesion load in the regression model, and is 0.66 with initial impairment and weighted lesion load. Conclusions: Our data shows the degree of motor impairment at 3 months after a first-ever ischemic stroke can be predicted by the overlap of the lesion with the canonical CST derived from age-matched healthy control subjects and the initial motor impairment measured in the acute phase.

Abstract WMP16: Improved Prediction of Hemorrhagic Transformation in Acute Stroke Patients Using Lowered Cerebral Blood Volume on MRI and Clinical Severity by NIHSS

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Sundeep Saini ◽  
Steven Warach ◽  
Marie Luby ◽  
Keyword(s):  
Image Registration ◽  
Acute Stroke ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Lesion Size ◽  
Hemorrhagic Transformation ◽  
Multinomial Regression ◽  
Stroke Patients ◽  
Pre Treatment ◽  
Iv Tpa

Objectives: Hemorrhagic transformation of the ischemic lesion is a common thrombolytic complication when treating acute stroke patients with standard IV-tPA. In a retrospective study we demonstrated that patients that have HT post-thrombolysis have a significantly lowered cerebral blood volume (CBV) on their pre-thrombolysis MRI compared to non HT patients. The objective of this study was to determine prospectively whether reduced CBV in combination with stroke severity can predict the occurrence of HT in patients post-thrombolysis. Methods: Patients were selected from the NINDS Stroke Registry if they: had an acute ischemic stroke located in the MCA territory, were treated with standard IV-tPA, had a pre-treatment MRI with evaluable DWI and PWI, and had post-treatment MRI evaluation for HT. A rater calculated CBV maps in PMA™ (ASIST-Japan) and performed image registration and region of interest analyses in MIPAV™ (NIH). The rater repeated the CBV analysis without image registration using DICOM software available on the scanner. Multinomial regression with covariates of baseline NIHSS, DWI lesion size, and CBV ratio was performed. All MRI scans were reviewed by expert readers blinded to the CBV analyses to determine the presence of HT using the ECASS-II criteria. Results: Seventy-six patients met the study criteria with a mean (SD) age of 68.1 (±14.1) years, median baseline NIHSS of 12 (IQR25-75: 5-18) and median onset to first MRI of 109 minutes (IQR25-75: 82-157). Thirty-six percent of patients (27/76) were positive for HT post-thrombolysis. The mean CBV ratio was 0.25 (STD ± 0.23) in the positive HT patients compared to 0.55 (STD ±0.24) in the negative HT patients. Multinomial regression demonstrated that the CBV ratio < 0.5 (p<0.006) and baseline NIHSS > 15 (p<0.034) significantly predicted the occurrence of any HT. The CBV ratio < 0.5 was the only independent predictor of severe HT, PH1 or PH2 (p<0.008). DWI lesion size using > 100 ml involvement of the MCA territory was not significant in predicting any or severe HT. Conclusions: Pre-treatment CBV ratio used in combination with baseline NIHSS are promising predictors of HT after standard IV-tPA. The ability to calculate CBV ratios directly on the scanner supports usage in acute intervention decision making.

Abstract WMP6: Delayed Device Access to the Occluded Target Vessel Predicts Worse Recanalization Rates and Poor Outcomes in Endovascular Therapy for Acute Stroke

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Marc Ribo ◽  
Brian Jankowitz ◽  
Syed Zaidi ◽  
Mouhammad Jumaa ◽  
Jennifer Oakley ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Infarct Volume ◽  
Univariate Analysis ◽  
Favorable Outcome ◽  
Anterior Circulation ◽  
Poor Outcome ◽  
Improved Outcomes ◽  
Poor Outcomes ◽  
Left Hemisphere Stroke ◽  
The Impact

During embolectomy for acute stroke, transfemoral access to occluded vessel may be technically difficult. We aim to study the impact of difficult catheter access to target artery. Methods: Single center review of anterior circulation stroke patients enrolled in prospective trials/registries (MR Rescue, MERCI, DEFUSE) requiring recording of time from groin puncture to first device deployment(Tdep). Patients were divided according to Tdep quartiles (Q): patients in Q4 were considered as difficult access. We recorded recanalization (TICI≥2a), complete recanalization (TICI≥2b), infarct volume(24h DWI), day 5 NIHSS, and favorable outcome (3 months mRS≤2). Results: We included 196 patients, mean age 66±14, median NIHSS 16(IQR:12-21). Overall outcomes were: median Tdep 52 min (36-77), recanalization 89.1%, complete recanalization 59.4%, favorable outcome 43.8%. We observed a positive correlation between Tdep and day 5 NIHSS (r=0.27; p=0.01) or 3 months mRS (r=0.26; p<0.01). Patients with difficult access (Q4: Tdep>77 min) had similar baseline NIHSS (16 Vs 17 p=0.58), time from symptom to procedure start (433 Vs 371min; p=0.28) and occlusion location (ICA/M1/M2: 46.7/42.2/11.1% Vs 39.1/54.3/6.5%; p=0.31). However, patients in Q4 had: longer IA procedures (153 vs 112 min;p<0.01), lower complete recanalization (41% Vs 66%;p<0.01), larger infarcts (87 Vs 53cc; p<0.01), higher day 5 NIHSS (15 Vs 9;p<0.01), and less favorable outcome (29.2% Vs 49%; p=0.02). After adjusting by age and time to reperfusion, a regression model identified admission NIHSS (OR% 1.12: 95%CI 1.02-1.21; p<0.01), age (OR% 1.03: 95%CI 1.01-1.06; p=0.01) and Tdep (OR% 1.02 95%CI 1.01-1.03; p=0.01) as independent predictors of poor outcome. In univariate analysis age>69, male gender and left hemisphere stroke were associated with difficult access. The combined presence of the 3 factors increased by 3.5 fold the likelihood of difficult access (OR:3.55 95%CI 1.5-8.6: p<0.01) Conclusion: Delayed device access to target occluded artery independently predicts poor outcome. Identification of difficult access using clinical scores or imaging may lead to alternative strategies; brachial, radial or cervical approaches that could result in shortened procedural times and improved outcomes

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