scholarly journals Indirect White Matter Pathways Are Associated With Treated Naming Improvement in Aphasia

2021 ◽  
pp. 154596832199905
Author(s):  
Janina Wilmskoetter ◽  
Julius Fridriksson ◽  
Alexandra Basilakos ◽  
Lorelei Phillip Johnson ◽  
Barbara Marebwa ◽  
...  
Keyword(s):  
White Matter ◽  
Treatment Outcomes ◽  
Inferior Frontal Gyrus ◽  
Brain Regions ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Middle Temporal ◽  
Pars Opercularis ◽  
Left Hemisphere Stroke ◽  
Linear Regressions

Background White matter disconnection of language-specific brain regions associates with worse aphasia recovery. Despite a loss of direct connections, many stroke survivors may maintain indirect connections between brain regions. Objective To determine (1) whether preserved direct connections between language-specific brain regions relate to better poststroke naming treatment outcomes compared to no direct connections and (2) whether for individuals with a loss of direct connections, preserved indirect connections are associated with better treatment outcomes compared to individuals with no connections. Methods We computed structural whole-brain connectomes from 69 individuals with chronic left-hemisphere stroke and aphasia who completed a 3-week-long language treatment that was supplemented by either anodal transcranial direct current stimulation (A-tDCS) or sham stimulation (S-tDCS). We determined differences in naming improvement between individuals with direct, indirect, and no connections using 1-way analyses of covariance and multivariable linear regressions. Results Independently of tDCS modality, direct or indirect connections between the inferior frontal gyrus pars opercularis and angular gyrus were both associated with a greater increase in correct naming compared to no connections ( P = .027 and P = .039, respectively). Participants with direct connections between the inferior frontal gyrus pars opercularis and middle temporal gyrus who received S-tDCS and participants with indirect connections who received A-tDCS significantly improved in naming accuracy. Conclusions Poststroke preservation of indirect white matter connections is associated with better treated naming improvement in aphasia even when direct connections are damaged. This mechanistic information can be used to stratify and predict treated naming recovery in individuals with aphasia.

scholarly journals Altered Spontaneous Neural Activity and Functional Connectivity in Parkinson’s Disease With Subthalamic Microlesion

2021 ◽  
Vol 15 ◽  
Author(s):  
Bei Luo ◽  
Yue Lu ◽  
Chang Qiu ◽  
Wenwen Dong ◽  
Chen Xue ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Functional Connectivity ◽  
Brain Activity ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Brain Regions ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Precentral Gyrus

BackgroundTransient improvement in motor symptoms are immediately observed in patients with Parkinson’s disease (PD) after an electrode has been implanted into the subthalamic nucleus (STN) for deep brain stimulation (DBS). This phenomenon is known as the microlesion effect (MLE). However, the underlying mechanisms of MLE is poorly understood.PurposeWe utilized resting state functional MRI (rs-fMRI) to evaluate changes in spontaneous brain activity and networks in PD patients during the microlesion period after DBS.MethodOverall, 37 PD patients and 13 gender- and age-matched healthy controls (HCs) were recruited for this study. Rs-MRI information was collected from PD patients three days before DBS and one day after DBS, whereas the HCs group was scanned once. We utilized the amplitude of low-frequency fluctuation (ALFF) method in order to analyze differences in spontaneous whole-brain activity among all subjects. Furthermore, functional connectivity (FC) was applied to investigate connections between other brain regions and brain areas with significantly different ALFF before and after surgery in PD patients.ResultRelative to the PD-Pre-DBS group, the PD-Post-DBS group had higher ALFF in the right putamen, right inferior frontal gyrus, right precentral gyrus and lower ALFF in right angular gyrus, right precuneus, right posterior cingulate gyrus (PCC), left insula, left middle temporal gyrus (MTG), bilateral middle frontal gyrus and bilateral superior frontal gyrus (dorsolateral). Functional connectivity analysis revealed that these brain regions with significantly different ALFF scores demonstrated abnormal FC, largely in the temporal, prefrontal cortices and default mode network (DMN).ConclusionThe subthalamic microlesion caused by DBS in PD was found to not only improve the activity of the basal ganglia-thalamocortical circuit, but also reduce the activity of the DMN and executive control network (ECN) related brain regions. Results from this study provide new insights into the mechanism of MLE.

scholarly journals Shared and Distinct Neuroanatomic Regions Critical for Tool-related Action Production and Recognition: Evidence from 131 Left-hemisphere Stroke Patients

2015 ◽  
Vol 27 (12) ◽  
pp. 2491-2511 ◽  
Author(s):  
Leyla Y. Tarhan ◽  
Christine E. Watson ◽  
Laurel J. Buxbaum
Keyword(s):  
Left Hemisphere ◽  
Mirror Neuron System ◽  
Inferior Frontal Gyrus ◽  
Occipital Cortex ◽  
Neural Substrates ◽  
Middle Temporal Gyrus ◽  
Stroke Patients ◽  
Middle Temporal ◽  
Impaired Performance ◽  
Left Hemisphere Stroke

The inferior frontal gyrus and inferior parietal lobe have been characterized as human homologues of the monkey “mirror neuron” system, critical for both action production (AP) and action recognition (AR). However, data from brain lesion patients with selective impairment on only one of these tasks provide evidence of neural and cognitive dissociations. We sought to clarify the relationship between AP and AR, and their critical neural substrates, by directly comparing performance of 131 chronic left-hemisphere stroke patients on both tasks—to our knowledge, the largest lesion-based experimental investigation of action cognition to date. Using voxel-based lesion-symptom mapping, we found that lesions to primary motor and somatosensory cortices and inferior parietal lobule were associated with disproportionately impaired performance on AP, whereas lesions to lateral temporo-occipital cortex were associated with a relatively rare pattern of disproportionately impaired performance on AR. In contrast, damage to posterior middle temporal gyrus was associated with impairment on both AP and AR. The distinction between lateral temporo-occipital cortex, critical for recognition, and posterior middle temporal gyrus, important for both tasks, suggests a rough gradient from modality-specific to abstract representations in posterior temporal cortex, the first lesion-based evidence for this phenomenon. Overall, the results of this large patient study help to bring closure to a long-standing debate by showing that tool-related AP and AR critically depend on both common and distinct left hemisphere neural substrates, most of which are external to putative human mirror regions.

scholarly journals fMRI Evidence for Dual Routes to the Mental Lexicon in Visual Word Recognition

2002 ◽  
Vol 14 (1) ◽  
pp. 11-23 ◽  
Author(s):  
Christian J. Fiebach ◽  
Angela D. Friederici ◽  
Karsten Müller ◽  
D. Yves von Cramon
Keyword(s):  
Word Processing ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Brain Regions ◽  
Visual Word ◽  
Middle Temporal Gyrus ◽  
Lexical Selection ◽  
Left Inferior Frontal Gyrus ◽  
Pars Opercularis ◽  
Left Middle Temporal Gyrus

Event-related fMRI was used to investigate lexical decisions to words of high and low frequency of occurrence and to pseudowords. The results obtained strongly support dual-route models of visual word processing. By contrasting words with pseudowords, bilateral occipito-temporal brain areas and posterior left middle temporal gyrus (MTG) were identified as contributing to the successful mapping of orthographic percepts onto visual word form representations. Low-frequency words and pseudowords elicited greater activations than high-frequency words in the superior pars opercularis [Brodmann's area (BA) 44] of the left inferior frontal gyrus (IFG), in the anterior insula, and in the thalamus and caudate nucleus. As processing of these stimuli during lexical search is known to rely on phonological information, it is concluded that these brain regions are involved in grapheme-to-phoneme conversion. Activation in the pars triangularis (BA 45) of the left IFG was observed only for low-frequency words. It is proposed that this region is involved in processes of lexical selection.

scholarly journals Neuroanatomical dissociations of syntax and semantics revealed by lesion-symptom mapping

2020 ◽  
Author(s):  
William Matchin ◽  
Alexandra Basilakos ◽  
Dirk-Bart den Ouden ◽  
Brielle C. Stark ◽  
Gregory Hickok ◽  
...  
Keyword(s):  
Brain Damage ◽  
Inferior Frontal Gyrus ◽  
Semantic Category ◽  
Brain Regions ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Word Fluency ◽  
Specific Language Impairments ◽  
Lesion Symptom Mapping ◽  
High Level

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.

scholarly journals Speaking in the Brain: The Interaction between Words and Syntax in Sentence Production

2020 ◽  
Vol 32 (8) ◽  
pp. 1466-1483
Author(s):  
Atsuko Takashima ◽  
Agnieszka Konopka ◽  
Antje Meyer ◽  
Peter Hagoort ◽  
Kirsten Weber
Keyword(s):  
Language Production ◽  
Inferior Frontal Gyrus ◽  
Sentence Production ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Temporal Region ◽  
Middle Temporal ◽  
Sentence Level ◽  
Left Posterior ◽  
Language Network

This neuroimaging study investigated the neural infrastructure of sentence-level language production. We compared brain activation patterns, as measured with BOLD-fMRI, during production of sentences that differed in verb argument structures (intransitives, transitives, ditransitives) and the lexical status of the verb (known verbs or pseudoverbs). The experiment consisted of 30 mini-blocks of six sentences each. Each mini-block started with an example for the type of sentence to be produced in that block. On each trial in the mini-blocks, participants were first given the (pseudo-)verb followed by three geometric shapes to serve as verb arguments in the sentences. Production of sentences with known verbs yielded greater activation compared to sentences with pseudoverbs in the core language network of the left inferior frontal gyrus, the left posterior middle temporal gyrus, and a more posterior middle temporal region extending into the angular gyrus, analogous to effects observed in language comprehension. Increasing the number of verb arguments led to greater activation in an overlapping left posterior middle temporal gyrus/angular gyrus area, particularly for known verbs, as well as in the bilateral precuneus. Thus, producing sentences with more complex structures using existing verbs leads to increased activation in the language network, suggesting some reliance on memory retrieval of stored lexical–syntactic information during sentence production. This study thus provides evidence from sentence-level language production in line with functional models of the language network that have so far been mainly based on single-word production, comprehension, and language processing in aphasia.

scholarly journals Diffusion Tensor Imaging Studies on Chinese Patients with Social Anxiety Disorder

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Changjian Qiu ◽  
Chunyan Zhu ◽  
Jingna Zhang ◽  
Xiaojing Nie ◽  
Yuan Feng ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Anxiety Disorder ◽  
White Matter ◽  
Diffusion Tensor ◽  
Inferior Frontal Gyrus ◽  
Middle Temporal Gyrus ◽  
Left Inferior Frontal Gyrus ◽  
Middle Temporal ◽  
Adc Values ◽  
Left Insula

The aim of this study was to explore white-matter disruption in social anxiety disorder (SAD) patients by using diffusion tensor imaging (DTI) and to investigate the relationship between cerebral abnormalities and the severity of the symptoms. Eighteen SAD patients and age- and gender-matched healthy controls were recruited. DTI scans were performed to measure fractional anisotropy (FA) and apparent diffusion coefficient (ADC) for each subject. We used voxel-based analysis to determine the differences of FA and ADC values between the two groups with two-samplet-tests. The SAD patient showed significantly decreased FA values in the white matter of the left insula, left inferior frontal gyrus, left middle temporal gyrus, and left inferior parietal gyrus and increased ADC values in the left insula, bilateral inferior frontal gyrus, bilateral middle temporal gyrus, and left inferior parietal gyrus. In SAD patients, we observed a significant negative correlation between FA values in the left insula and the total LSAS scores and a positive correlation between the ADC values in the left inferior frontal gyrus and the total LSAS scores. Above results suggested that white-matter microstructural changes might contribute to the neuropathology of SAD.

scholarly journals Speaking in the brain: The interaction between words and syntax in producing sentences

2019 ◽  
Author(s):  
Atsuko Takashima ◽  
Agnieszka Konopka ◽  
Antje Meyer ◽  
Peter Hagoort ◽  
Kirsten Weber
Keyword(s):  
Language Production ◽  
Inferior Frontal Gyrus ◽  
Sentence Production ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Temporal Region ◽  
Middle Temporal ◽  
Sentence Level ◽  
Core Language ◽  
Language Network

AbstractThis neuroimaging study investigated the neural infrastructure of sentence-level language production. We compared brain activation patterns, as measured with BOLD-fMRI, during production of sentences which differed in verb argument structures (intransitives, transitives, ditransitives) and the lexical status of the verb (known verbs or pseudo-verbs). An example for the type of sentence to be produced started a mini-block of six sentences with the same structure. For each trial, participants were first given the (pseudo-)verb followed by three geometric shapes to serve as verb arguments in the sentences. Production of sentences with known verbs yielded greater activation compared to those with pseudo-verbs in the core language network of left inferior frontal gyrus, the left posterior middle temporal gyrus, and a more posterior middle temporal region extending into the angular gyrus (LpMTG/AG), analogous to effects observed in language comprehension. Increasing the number of verb arguments led to greater activation in an overlapping left pMTG/AG area, particularly for known verbs, as well as in the bilateral precuneus. Thus, producing sentences with more complex structures using existing verbs lead to increased activation in the language network, suggesting some reliance on memory retrieval of stored lexical-syntactic information during sentence production. This study thus provides evidence from sentence-level language production in line with functional models of the language network that have so far been mainly based on single word production, comprehension and processing in aphasia.

Relationship between symptom dimensions and white matter alterations in obsessive-compulsive disorder

2016 ◽  
Vol 29 (3) ◽  
pp. 153-163 ◽  
Author(s):  
Michiyo Yagi ◽  
Yoshiyuki Hirano ◽  
Michiko Nakazato ◽  
Kiyotaka Nemoto ◽  
Kazuhiro Ishikawa ◽  
...  
Keyword(s):  
White Matter ◽  
Obsessive Compulsive Disorder ◽  
Diffusion Tensor ◽  
Inferior Frontal Gyrus ◽  
Mean Diffusivity ◽  
Brain Regions ◽  
Middle Temporal Gyrus ◽  
Obsessive Compulsive ◽  
Symptom Dimensions ◽  
Compulsive Disorder

ObjectiveTo investigate the relationship between the severities of symptom dimensions in obsessive-compulsive disorder (OCD) and white matter alterations.MethodsWe applied tract-based spatial statistics for diffusion tensor imaging (DTI) acquired by 3T magnetic resonance imaging. First, we compared fractional anisotropy (FA) between 20 OCD patients and 30 healthy controls (HC). Then, applying whole brain analysis, we searched the brain regions showing correlations between the severities of symptom dimensions assessed by Obsessive-Compulsive Inventory-Revised and FA in all participants. Finally, we calculated the correlations between the six symptom dimensions and multiple DTI measures [FA, axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD)] in a region-of-interest (ROI) analysis and explored the differences between OCD patients and HC.ResultsThere were no between-group differences in FA or brain region correlations between the severities of symptom dimensions and FA in any of the participants. ROI analysis revealed negative correlations between checking severity and left inferior frontal gyrus white matter and left middle temporal gyrus white matter and a positive correlation between ordering severity and right precuneus in FA in OCD compared with HC. We also found negative correlations between ordering severity and right precuneus in RD, between obsessing severities and right supramarginal gyrus in AD and MD, and between hoarding severity and right insular gyrus in AD.ConclusionOur study supported the hypothesis that the severities of respective symptom dimensions are associated with different patterns of white matter alterations.

scholarly journals IN VIVO ASSESSMENT OF AMYLOID AND GLUCOSE SIGNATURES IN SUBJECTIVE COGNITIVE DECLINE SUBJECTS

2021 ◽  
pp. 2140018
Author(s):  
XIAOFENG YU ◽  
ZHILONG ZHU ◽  
SHUZHAN ZHENG ◽  
JIAN JIANG ◽  
JUANJUAN JIANG ◽  
...  
Keyword(s):  
Cognitive Decline ◽  
Characteristic Curve ◽  
Standardized Uptake Value ◽  
Brain Regions ◽  
Middle Temporal Gyrus ◽  
Subjective Cognitive Decline ◽  
Middle Temporal ◽  
Main Effect ◽  
Heschl Gyrus

Subjective cognitive decline (SCD), characterized by self-perceived subtle cognitive impairment ahead of the appearance of explicit and measurable cognitive deficits, is regarded as the preclinical manifestation of the pathological change continuum of Alzheimer’s disease (AD). We were committed to exploring the amyloid and glucose metabolic signatures related to imminent brain metabolic changes in SCD subjects. This study included 39 subjects (mean age = 71.9 years; 14 males and 25 females) diagnosed with SCD disease and 39 gender-matched healthy controls (HCs) (mean age = 75.2; 16 males and 23 females) with brain [18F] fluorodeoxyglucose positron emission tomography (PET) images and [18F] florbetapir PET images. The standardized uptake value ratios (SUVRs) of PET images within the regions of interest (ROIs) were calculated. Inter-group SUVR differences were assessed by two-sample [Formula: see text]-testing and receiver operating characteristic curve (ROC) analyses. A generalized linear model (GLM) was employed to evaluate the correlations between amyloid and FDG uptake. Compared with HCs, SCD subjects showed significantly increased amyloid SUVR, as well as significantly increased glucose SUVR in the olfactory, amygdala, thalamus, heschl gyrus, superior and middle temporal gyrus and temporal pole (all [Formula: see text]). The amyloid SUVR of thalamus was found to have a better ROC result (area under the curve (AUC): 0.77, 95% confidence interval (CI): 0.66–0.86) in the HC group, as was the case with the glucose SUVR of the middle temporal gyrus (AUC: 0.83, 95% CI: 0.73–0.91). There were significant positive correlations between amyloid and glucose SUVRs ([Formula: see text]). The amyloid SUVR of the thalamus showed a significantly better main effect (odd ratio [Formula: see text] 2.91, 95% CI: 1.44–6.7, [Formula: see text]), and the glucose SUVR of the heschl gyrus indicated an enhanced main effect (odd ratio [Formula: see text] 5.08, 95% CI: 1.86–18.15, [Formula: see text]). SCD subjects demonstrated significant amyloid accumulation and glucose hypermetabolism in specific brain regions, and amyloid pathology overlapped with regions of glucose abnormality. These findings may advance the understanding of imminent pathological changes in the SCD stage and help to provide clinical guidelines for interventional management.

scholarly journals Brain Activation of College Students in China With Premenstrual Syndrome Localized by BOLD-fMRI

2021 ◽  
Author(s):  
Dongmei Gao ◽  
Mingzhou Gao ◽  
Li An ◽  
Yanhong Yu ◽  
Jieqiong Wang ◽  
...  
Keyword(s):  
College Students ◽  
Premenstrual Syndrome ◽  
Brain Area ◽  
Inferior Frontal Gyrus ◽  
Brain Regions ◽  
Anterior Lobe ◽  
Middle Temporal Gyrus ◽  
Cerebellar Tonsil ◽  
Bold Fmri ◽  
Significant Difference

Abstract Background: Most studies on the mechanism behind premenstrual syndrome (PMS) have focused on fluctuating hormones, but little evidence exists regarding functional abnormalities in the affected brain regions of college students. Thus, the aim of this study is to localize PMS's abnormal brain regions by BOLD-fMRI in college students.Methods: Thirteen PMS patients and fifteen healthy control (HC) subjects underwent a BOLD-fMRI scan during the luteal phase induced by depressive emotion pictures. The BOLD-fMRI data were processed by SPM 8 software and rest software based on MATLAB platform. Each cluster volume threshold (cluster) was greater than 389 continuous voxels, and the brain area with single voxel threshold P < 0.05 (after correction) was defined as the area with a significant difference. The emotion report form and the instruction implementation checklist were used to evaluate the emotion induced by picture.Results: Compared to the HC, right inferior occipital gyrus, right middle occipital gyrus, right lingual gyrus, right fusiform gyrus, right inferior temporal gyrus, cerebelum_crus1_R，cerebelum_6_R, culmen, the cerebellum anterior lobe, tuber, cerebellar tonsil of PMS patients were enhanced activation. Sub-lobar，sub-gyral，extra-nuclear，right orbit part of superior frontal gyrus, right middle temporal gyrus, right Orbit part of inferior frontal gyrus, limbic lobe, right insula, bilateral anterior and adjacent cingulate gyrus, bilateral caudate, caudate head, bilateral putamen, left globus pallidus were decreased activation.Conclusion: Our findings may improve our understanding of the neural mechanisms involved in PMS.

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