Abstract P356: Wernicke’s Vertical Occipital Fasciculus in Post-Stroke Reading

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Zafer Keser ◽  
Erin L Meier ◽  
Melissa D Stockbridge ◽  
Bonnie L Breining ◽  
Rajani Sebastian ◽  
...  
Keyword(s):  
Oral Reading ◽  
Picture Naming ◽  
Diffusion Tensor ◽  
Critical Role ◽  
Preliminary Evidence ◽  
Boston Naming Test ◽  
Cortical Projection ◽  
Hemispheric Stroke ◽  
Partial Correlations ◽  
Language Areas

Introduction: The vertical-occipital fasciculus (VOF), which was initially described by Wernicke more than a century ago but recently rediscovered, connects visual association cortices to the posterior language areas. We hypothesized that the vertical-occipital fasciculus plays a critical role in reading. Methods: Thirty-two participants with subacute to chronic left hemispheric stroke leading to varying degrees of aphasia were enrolled in the study and underwent concurrent diffusion tensor imaging (DTI) and language assessment. Assessments included the Boston Diagnostic Aphasia Examination (BDAE) to assess oral reading and reading comprehension and the Boston Naming Test to assess picture naming. Two major cortico-cortical projection pathways, VOF, connected with posterior language cortices and frontal aslant tract (FAT), connecting anterior language areas, were mapped with deterministic tractography and quantified bilaterally. We conducted partial correlations between fractional anisotropy (FA) values of the tracts and reading and picture naming scores, controlling for age, education, and total lesion load. We corrected for multiple comparisons at the false discovery rate (FDR) (p<0.05). Results: FA of left VOF was found to be significantly correlated with BDAE total reading scores (r=0.49, p=0.004), and this remained significant after FDR correction (p=0.03). Although a significant correlation was seen between picture naming and left VOF FA (r=0.41, p=0.02), and right VOF FA (r=0.37, p=0.04), these associations were not significant after FDR correction (p>0.05). FAT FA values were not significantly associated with oral reading or picture naming tests. Conclusion: This study provides preliminary evidence that left VOF plays a potential role in reading after left hemispheric stroke.

scholarly journals Right Hemispheric Homologous Language Pathways Negatively Predicts Poststroke Naming Recovery

Stroke ◽  
2020 ◽  
Vol 51 (3) ◽  
pp. 1002-1005 ◽  
Author(s):  
Zafer Keser ◽  
Rajani Sebastian ◽  
Khader M. Hasan ◽  
Argye E. Hillis
Keyword(s):  
Diffusion Tensor Imaging ◽  
Left Hemisphere ◽  
Structural Integrity ◽  
Right Hemisphere ◽  
Diffusion Tensor ◽  
Preliminary Evidence ◽  
Arcuate Fasciculus ◽  
Hemispheric Stroke ◽  
Language Pathways

Background and Purpose— Stroke is the leading cause of disability in United States, and aphasia is a common sequela after a left hemisphere stroke. Functional imaging and brain stimulation studies show that right hemisphere structures are detrimental to aphasia recovery but evidence from diffusion tensor imaging is lacking. We investigated the role of homologous language pathways in naming recovery after left hemispheric stroke. Methods— Patients with aphasia after a left hemispheric stroke underwent naming assessment using the Boston Naming Test and diffusion tensor imaging at the acute and chronic time points. We analyzed diffusion tensor imaging of right arcuate fasciculus and frontal aslant tracts. We used Wilcoxon rank-sum test to evaluate structural lateralization patterns and partial Spearman correlation/multivariate generalized linear model to determine the role of right arcuate fasciculus and frontal aslant tracts in naming recovery after controlling for confounders. Results were corrected for multiple comparisons. Results— On average, the structural integrity of left language pathways deteriorated more than their right homologs, such that there was rightward lateralization in the chronic stage. Regression/correlation analyses showed that greater preservation of tract integrity of right arcuate fasciculus was associated with poorer naming recovery. Conclusions— Our study provides preliminary evidence that preservation of right homologs of language pathways is associated with poor recovery of naming after a left hemispheric stroke, consistent with previous evidence that maintaining greater reliance on left hemisphere structures is associated with better language recovery.

scholarly journals Detection of acute ventilatory problems via magnetic induction in a newborn animal model

2021 ◽  
Author(s):  
Sabrina C. Behr ◽  
Christopher Platen ◽  
Pascal Vetter ◽  
Nicole Heussen ◽  
Steffen Leonhardt ◽  
...  
Keyword(s):  
Early Detection ◽  
Magnetic Induction ◽  
Side Information ◽  
Pulmonary Ventilation ◽  
Critical Role ◽  
Preliminary Evidence ◽  
List Type ◽  
Newborn Animal ◽  
Newborn Piglets ◽  
Patient Side

Abstract Background Magnetic induction measurement (MIM) is a noninvasive method for the contactless registration of respiration in newborn piglets by using measurement coils positioned at the bottom of an incubator. Acute pulmonary problems may be determinants of poor neurological and psychomotor outcomes in preterm infants. The current study tested the detection of pulmonary ventilation disorders via MIM in 11 newborn piglets. Methods Six measurement coils determined changes in magnetic induction, depending on the ventilation of the lung, in comparison with flow resistance. Contactless registration of induced acute pulmonary ventilation disorders (apnea, atelectasis, pneumothorax, and aspiration) was detected by MIM. Results All pathologies except aspiration were detected by MIM. Significant changes occurred after induction of apnea (three coils), malposition of the tube (one coil), and pneumothorax (three coils) (p ≤ 0.05). No significant changes occurred after induction of aspiration (p = 0.12). Conclusions MIM seems to have some potential to detect acute ventilation disorders in newborn piglets. The location of the measurement coil related to the animal’s position plays a critical role in this process. In addition to an early detection of acute pulmonary problems, potential information pointing to a therapeutic intervention, for example, inhalations or medical respiratory analepsis, may be conceivable with MIM in the future. Impact MIM seems to be a method in which noncontact ventilation disorders of premature and mature infants can be detected. This study is an extension of the experimental setup to obtain preliminary evidence for detection of respiratory activity in neonatal piglets. For the first time, MIM is used to register acute ventilation problems of neonates. The possibility of an early detection of acute ventilation problems via MIM may provide an opportunity to receive patient-side information for therapeutical interventions like inhalations or medical respiratory analepsis.

Remodeling of cardiac fiber structure after infarction in rats quantified with diffusion tensor MRI

2003 ◽  
Vol 285 (3) ◽  
pp. H946-H954 ◽  
Author(s):  
Junjie Chen ◽  
Sheng-Kwei Song ◽  
Wei Liu ◽  
Mark McLean ◽  
J. Stacy Allen ◽  
...  
Keyword(s):  
Structural Changes ◽  
Diffusion Tensor ◽  
Critical Role ◽  
Coronary Artery Occlusion ◽  
Tissue Level ◽  
Functional Adaptation ◽  
Angular Deviation ◽  
Diffusion Anisotropy ◽  
Structural Remodeling ◽  
Anisotropy Index

Structural remodeling of myocardium after infarction plays a critical role in functional adaptation. Diffusion tensor magnetic resonance imaging (DTMRI) provides a means for rapid and nondestructive characterization of the three-dimensional fiber architecture of cardiac tissues. In this study, microscopic structural changes caused by MI were evaluated in Fischer 344 rats 4 wk after infarct surgery. DTMRI studies were performed on 15 excised, formalin-fixed rat hearts of both infarct (left anterior descending coronary artery occlusion, n = 8) and control (sham, n = 7) rats. Infarct myocardium exhibited increased water diffusivity (41% increase in trace values) and decreased diffusion anisotropy (37% decrease in relative anisotropy index). The reduced diffusion anisotropy correlated negatively with microscopic fiber disarray determined by histological analysis ( R = 0.81). Transmural courses of fiber orientation angles in infarct zones were similar to those of normal myocardium. However, regional angular deviation of the diffusion tensor increased significantly in the infarct myocardium and correlated strongly with microscopic fiber disarray ( R = 0.86). These results suggest that DTMRI may provide a valuable tool for defining structural remodeling in diseased myocardium at the cellular and tissue level.

scholarly journals In Vivo Characterization of Cortical and White Matter Microstructural Pathology in Growth Hormone-Secreting Pituitary Adenoma

2021 ◽  
Vol 11 ◽  
Author(s):  
Taoyang Yuan ◽  
Jianyou Ying ◽  
Chuzhong Li ◽  
Lu Jin ◽  
Jie Kang ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Pituitary Adenoma ◽  
White Matter ◽  
Diffusion Tensor ◽  
Critical Role ◽  
Mean Diffusivity ◽  
Occipital Cortex ◽  
Test Surface ◽  
Neuropsychological Dysfunction

BackgroundThe growth hormone (GH) and insulin-like-growth factor 1 (IGF-1) axis has long been recognized for its critical role in brain growth, development. This study was designed to investigate microstructural pathology in the cortex and white matter in growth hormone-secreting pituitary adenoma, which characterized by excessive secretion of GH and IGF-1.Methods29 patients with growth hormone-secreting pituitary adenoma (acromegaly) and 31 patients with non-functional pituitary adenoma as controls were recruited and assessed using neuropsychological test, surface-based morphometry, T1/T2-weighted myelin-sensitive magnetic resonance imaging, neurite orientation dispersion and density imaging, and diffusion tensor imaging.ResultsCompared to controls, we found 1) acromegaly had significantly increased cortical thickness throughout the bilateral cortex (pFDR &lt; 0.05). 2) T1/T2-weighted ratio in the cortex were decreased in the bilateral occipital cortex and pre/postcentral central gyri but increased in the bilateral fusiform, insular, and superior temporal gyri in acromegaly (pFDR &lt; 0.05). 3) T1/T2-weighted ratio were decreased in most bundles, and only a few areas showed increases in acromegaly (pFDR &lt; 0.05). 4) Neurite density index (NDI) was significantly lower throughout the cortex and bundles in acromegaly (pTFCE &lt; 0.05). 5) lower fractional anisotropy (FA) and higher mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) in extensive bundles in acromegaly (pTFCE &lt; 0.05). 6) microstructural pathology in the cortex and white matter were associated with neuropsychological dysfunction in acromegaly.ConclusionsOur findings suggested that long-term persistent and excess serum GH/IGF-1 levels alter the microstructure in the cortex and white matter in acromegaly, which may be responsible for neuropsychological dysfunction.

Impairment and Plasticity of Language-Related White Matter in Patients With Brain Arteriovenous Malformations

Stroke ◽  
2021 ◽  
Author(s):  
Xiaofeng Deng ◽  
Hu Yin ◽  
Yan Zhang ◽  
Dong Zhang ◽  
Shuo Wang ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Disease Model ◽  
Control Group ◽  
Language Functions ◽  
Traditional Language ◽  
The Difference ◽  
Uncinate Fascicle ◽  
Myelin Deficits ◽  
Language Areas

Background and Purpose: Language dysfunction is rarely seen in patients with unruptured brain arteriovenous malformation (AVM) albeit the AVM nidus involving language areas, which provides a unique disease model to study language reorganization. The objective of this study was to investigate the impairment and reorganization patterns and characteristics of language-related white matter in AVMs located at different brain areas. Methods: Thirty-three patients with AVMs involving language areas were prospectively enrolled. Patients were categorized into 3 groups according to the lesion locations: the frontal (14 patients), temporal (15 patients), and parietal groups (4 patients). Thirty age- and sex-matched healthy controls were enrolled as comparison. All participants underwent diffusion tensor imaging scans, and automated fiber quantification method was applied to quantitatively study the difference of segmented language-related white matter connectivity between 3 AVM groups and control group. Results: Language functions were normal in all subjects according to Western Aphasia Battery test. In the frontal group, fractional anisotropy (FA) value decreased in the left arcuate fascicle and increased in left superior longitudinal fasciculus and uncinate fascicle; in the temporal group, FA values decreased in left inferior fronto-occipital fascicle and inferior longitudinal fascicle and increased in right anterior thalamic radiation and uncinate fascicle; in the parietal group, FA values decreased in left arcuate fascicle and inferior longitudinal fascicle and increased in bilateral anterior thalamic radiations and uncinate fascicles and right inferior fronto-occipital fascicle. In fascicles with decreased FA values, the increase of radial diffusivity was common, and fascicles with increased FA values usually presented along with increased axial diffusivity values. Conclusions: Remodeling of language-related white matter occurs when traditional language areas are involved by AVM nidus, and its reorganization patterns vary with locations of AVM nidus. Fascicle impairment is mainly caused by the myelin deficits, and its plasticity may be dominated by the axon remodeling procedure.

scholarly journals Phenotypical resistance correlation networks for 10 non-typhoidalSalmonellasubpopulations in an active antimicrobial surveillance programme

2018 ◽  
Vol 146 (8) ◽  
pp. 991-1002 ◽  
Author(s):  
W. J. Love ◽  
K. A. Zawack ◽  
J. G. Booth ◽  
Y. T. Gröhn ◽  
C. Lanzas
Keyword(s):  
Critical Role ◽  
Genetic Correlations ◽  
Network Models ◽  
Indirect Selection ◽  
Chloramphenicol Resistance ◽  
Surveillance Programme ◽  
Correlation Networks ◽  
Antimicrobial Surveillance ◽  
Partial Correlations ◽  
Selection For

AbstractAntimicrobials play a critical role in treating cases of invasive non-typhoidal salmonellosis (iNTS) and other diseases, but efficacy is hindered by resistant pathogens. Selection for phenotypical resistance may occur via several mechanisms. The current study aims to identify correlations that would allow indirect selection of increased resistance to ceftriaxone, ciprofloxacin and azithromycin to improve antimicrobial stewardship. These are medically important antibiotics for treating iNTS, but these resistances persist in non-TyphiSalmonellaserotypes even though they are not licensed for use in US food animals. A set of 2875Salmonella entericaisolates collected from animal sources by the National Antimicrobial Resistance Monitoring System were stratified in to 10 subpopulations based on serotype and host species. Collateral resistances in each subpopulation were estimated as network models of minimum inhibitory concentration partial correlations. Ceftriaxone sensitivity was correlated with otherβ-lactam resistances, and less commonly resistances to tetracycline, trimethoprim-sulfamethoxazole or kanamycin. Azithromycin resistance was frequently correlated with chloramphenicol resistance. Indirect selection for ciprofloxacin resistance via collateral selection appears unlikely. Density of the ACSSuT subgraph resistance aligned well with the phenotypical frequency. The current study identifies several important resistances in iNTS serotypes and further research is needed to identify the causative genetic correlations.

scholarly journals Change in Right Inferior Longitudinal Fasciculus Integrity Is Associated With Naming Recovery in Subacute Poststroke Aphasia

2020 ◽  
Vol 34 (9) ◽  
pp. 784-794
Author(s):  
Marieke Blom-Smink ◽  
Marjolein Verly ◽  
Kerstin Spielmann ◽  
Marion Smits ◽  
Gerard M. Ribbers ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Change Score ◽  
Strong Positive Correlation ◽  
Boston Naming Test ◽  
Inferior Longitudinal Fasciculus ◽  
Deterministic Tractography ◽  
The Right ◽  
Left Hemisphere Stroke ◽  
Microstructural Integrity

Background. Despite progress made in understanding functional reorganization patterns underlying recovery in subacute aphasia, the relation between recovery and changes in white matter structure remains unclear. Objective. To investigate changes in dorsal and ventral language white matter tract integrity in relation to naming recovery in subacute poststroke aphasia. Methods. Ten participants with aphasia after left-hemisphere stroke underwent language testing and diffusion tensor imaging twice within 3 months post onset, with a 1-month interval between sessions. Deterministic tractography was used to bilaterally reconstruct the superior longitudinal fasciculus (SLF), inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), middle longitudinal fasciculus (MdLF), and uncinate fasciculus (UF). Per tract, the mean fractional anisotropy (FA) was extracted as a measure of microstructural integrity. Naming accuracy was assessed with the Boston Naming Test (BNT). Correlational analyses were performed to investigate the relationship between changes in FA values and change in BNT score. Results. A strong positive correlation was found between FA change in the right ILF within the ventral stream and change on the BNT ( r = 0.91, P < .001). An increase in FA in the right ILF was associated with considerable improvement of naming accuracy (range BNT change score: 12-14), a reduction with limited improvement or slight deterioration. No significant correlations were found between change in naming accuracy and FA change in any of the other right or left ventral and dorsal language tracts. Conclusions. Naming recovery in subacute aphasia is associated with change in the integrity of the right ILF.

Cortical Projection Topography of the Human Splenium: Hemispheric Asymmetry and Individual Differences

2010 ◽  
Vol 22 (8) ◽  
pp. 1662-1669 ◽  
Author(s):  
Mary Colvin Putnam ◽  
Megan S. Steven ◽  
Karl W. Doron ◽  
Adam C. Riggall ◽  
Michael S. Gazzaniga
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Hemispheric Asymmetry ◽  
Right Hemisphere ◽  
Diffusion Tensor ◽  
Cortical Projection ◽  
Interhemispheric Communication ◽  
Posterior Portion ◽  
Interhemispheric Connectivity ◽  
Visual Areas

The corpus callosum is the largest white matter pathway in the human brain. The most posterior portion, known as the splenium, is critical for interhemispheric communication between visual areas. The current study employed diffusion tensor imaging to delineate the complete cortical projection topography of the human splenium. Homotopic and heterotopic connections were revealed between the splenium and the posterior visual areas, including the occipital and the posterior parietal cortices. In nearly one third of participants, there were homotopic connections between the primary visual cortices, suggesting interindividual differences in splenial connectivity. There were also more instances of connections with the right hemisphere, indicating a hemispheric asymmetry in interhemispheric connectivity within the splenium. Combined, these findings demonstrate unique aspects of human interhemispheric connectivity and provide anatomical bases for hemispheric asymmetries in visual processing and a long-described hemispheric asymmetry in speed of interhemispheric communication for visual information.

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