Localization of Primary Language Areas by Arcuate Fascicle Fiber Tracking

Neurosurgery ◽  
2011 ◽  
Vol 70 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Lennart Henning Stieglitz ◽  
Kathleen Seidel ◽  
Roland Wiest ◽  
Jürgen Beck ◽  
Andreas Raabe
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Diffusion Tensor ◽  
Inferior Frontal Gyrus ◽  
Spatial Relationship ◽  
Primary Language ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Language Areas

Abstract BACKGROUND To reduce the risk of disabling postoperative functional deficit in patients with lesions in the dominant hemisphere, information about the localization of eloquent language areas is mandatory. OBJECTIVE To demonstrate the feasibility of arcuate fascicle (AF) tractography for proper localization of eloquent language areas in the superior temporal (STG) and inferior frontal gyrus (IFG). METHODS Between January and June 2010, we performed surgery in 13 patients with highly eloquent lesions with close spatial relationship to the primary language areas. All of them received preoperative diffusion tensor imaging for AF tractography. The STG and IFG were delineated at the ends of the AF. Five patients underwent functional magnetic resonance imaging of the primary language areas. The results were compared with tractography. RESULTS Tractography of the AF without prior knowledge of the localization of the STG and IFG was feasible in all cases. In the cases with functional magnetic resonance imaging, the activation maps matched the tractography results. In all but 1 patient, preservation of the primary language areas was possible, proven by the good neurological outcome. One patient suffered from a language dysfunction caused by a lesion in the medial and inferior temporal gyrus along the surgical pathway. CONCLUSION Tractography of the AF is a useful tool for identification of parts of the main primary language areas. Using tractography as a localization procedure to determine the primary language areas aids in the delineation of the STG and IFG and thus may help reduce the risk of postoperative permanent neurological deficit.

Investigating the Neural Correlates of the Affect Heuristic Using Functional Magnetic Resonance Imaging

2021 ◽  
pp. 1-14
Author(s):  
Kenny Skagerlund ◽  
Mikael Skagenholt ◽  
Paul J. Hamilton ◽  
Paul Slovic ◽  
Daniel Västfjäll
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Inferior Frontal Gyrus ◽  
Neural Correlates ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Left Inferior Frontal Gyrus ◽  
Affect Heuristic ◽  
Medial Frontal Gyrus

Abstract This study investigated the neural correlates of the so-called “affect heuristic,” which refers to the phenomenon whereby individuals tend to rely on affective states rather than rational deliberation of utility and probabilities during judgments of risk and utility of a given event or scenario. The study sought to explore whether there are shared regional activations during both judgments of relative risk and relative benefit of various scenarios, thus being a potential candidate of the affect heuristic. Using functional magnetic resonance imaging, we developed a novel risk perception task, based on a preexisting behavioral task assessing the affect heuristic. A whole-brain voxel-wise analysis of a sample of participants (n = 42) during the risk and benefit conditions revealed overlapping clusters in the left insula, left inferior frontal gyrus, and left medial frontal gyrus across conditions. Extraction of parameter estimates of these clusters revealed that activity of these regions during both tasks was inversely correlated with a behavioral measure assessing the inclination to use the affect heuristic. More activity in these areas during risk judgments reflect individuals' ability to disregard momentary affective impulses. The insula may be involved in integrating viscero-somatosensory information and forming a representation of the current emotional state of the body, whereas activity in the left inferior frontal gyrus and medial frontal gyrus indicates that executive processes may be involved in inhibiting the impulse of making judgments in favor of deliberate risk evaluations.

scholarly journals Brain Functional Magnetic Resonance Imaging Highlights Altered Connections and Functional Networks in Patients With Hypertension

Hypertension ◽  
2020 ◽  
Vol 76 (5) ◽  
pp. 1480-1490 ◽  
Author(s):  
Lorenzo Carnevale ◽  
Angelo Maffei ◽  
Alessandro Landolfi ◽  
Giovanni Grillea ◽  
Daniela Carnevale ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Resting State ◽  
Diffusion Tensor ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Attention Network ◽  
Dorsal Attention Network ◽  
The Brain

Hypertension is one of the main risk factors for vascular dementia and Alzheimer disease. To predict the onset of these diseases, it is necessary to develop tools to detect the early effects of vascular risk factors on the brain. Resting-state functional magnetic resonance imaging can investigate how the brain modulates its resting activity and analyze how hypertension impacts cerebral function. Here, we used resting-state functional magnetic resonance imaging to explore brain functional-hemodynamic coupling across different regions and their connectivity in patients with hypertension, as compared to subjects with normotension. In addition, we leveraged multimodal imaging to identify the signature of hypertension injury on the brain. Our study included 37 subjects (18 normotensives and 19 hypertensives), characterized by microstructural integrity by diffusion tensor imaging and cognitive profile, who were subjected to resting-state functional magnetic resonance imaging analysis. We mapped brain functional connectivity networks and evaluated the connectivity differences among regions, identifying the altered connections in patients with hypertension compared with subjects with normotension in the (1) dorsal attention network and sensorimotor network; (2) dorsal attention network and visual network; (3) dorsal attention network and frontoparietal network. Then we tested how diffusion tensor imaging fractional anisotropy of superior longitudinal fasciculus correlates with the connections between dorsal attention network and default mode network and Montreal Cognitive Assessment scores with a widespread network of functional connections. Finally, based on our correlation analysis, we applied a feature selection to highlight those most relevant to describing brain injury in patients with hypertension. Our multimodal imaging data showed that hypertensive brains present a network of functional connectivity alterations that correlate with cognitive dysfunction and microstructural integrity. Registration— URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02310217.

Language Functional Magnetic Resonance Imaging in Preoperative Assessment of Language Areas: Correlation with Direct Cortical Stimulation

Neurosurgery ◽  
2003 ◽  
Vol 52 (6) ◽  
pp. 1335-1347 ◽  
Author(s):  
Franck-Emmanuel Roux ◽  
Kader Boulanouar ◽  
Jean-Albert Lotterie ◽  
Mehdi Mejdoubi ◽  
James P. LeSage ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Left Hemisphere ◽  
Brain Mapping ◽  
Fmri Data ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Verb Generation ◽  
Language Areas

Abstract OBJECTIVE The aim of this study was to analyze the usefulness of preoperative language functional magnetic resonance imaging (fMRI), by correlating fMRI data with intraoperative cortical stimulation results for patients with brain tumors. METHODS Naming and verb generation tasks were used, separately or in combination, for 14 right-handed patients with tumors in the left hemisphere. fMRI data obtained were analyzed with SPM software, with two standard analysis thresholds (P < 0.005 and then P < 0.05). The fMRI data were then registered in a frameless stereotactic neuronavigational device and correlated with direct brain mapping results. We used a statistical model with the fMRI information as a predictor, spatially correlating each intraoperatively mapped cortical site with fMRI data integrated in the neuronavigational system (site-by-site correlation). Eight patients were also studied with language fMRI postoperatively, with the same acquisition protocol. RESULTS We observed high variability in signal extents and locations among patients with both tasks. The activated areas were located mainly in the left hemisphere in the middle and inferior frontal gyri (F2 and F3), the superior and middle temporal gyri (T1 and T2), and the supramarginal and angular gyri. A total of 426 cortical sites were tested for each task among the 14 patients. In frontal and temporoparietal areas, poor sensitivity of the fMRI technique was observed for the naming and verb generation tasks (22 and 36%, respectively) with P < 0.005 as the analysis threshold. Although not perfect, the specificity of the fMRI technique was good in all conditions (97% for the naming task and 98% for the verb generation task). Better correlation (sensitivity, 59%; specificity, 97%) was achieved by combining the two fMRI tasks. Variation of the analysis threshold to P < 0.05 increased the sensitivity to 66% while decreasing the specificity to 91%. Postoperative fMRI data (for the cortical brain areas studied intraoperatively) were in accordance with brain mapping results for six of eight patients. Complete agreement between pre- and postoperative fMRI studies and direct brain mapping results was observed for only three of eight patients. CONCLUSION With the paradigms and analysis thresholds used in this study, language fMRI data obtained with naming or verb generation tasks, before and after surgery, were imperfectly correlated with intraoperative brain mapping results. A better correlation could be obtained by combining the fMRI tasks. The overall results of this study demonstrated that language fMRI could not be used to make critical surgical decisions in the absence of direct brain mapping. Other acquisition protocols are required for evaluation of the potential role of language fMRI in the accurate detection of essential cortical language areas.

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