Exploration of the Mechanism Underlying the Association of Incident Microinfarct and Motor Deficit: A Preliminary Functional MRI Study

2021 ◽  
pp. 1-10
Author(s):  
Xiao Luo ◽  
Hui Hong ◽  
Shuyue Wang ◽  
Kaicheng Li ◽  
Qingze Zeng ◽  
...  
Keyword(s):  
Motor Function ◽  
Inferior Frontal Gyrus ◽  
Motor Impairment ◽  
Motor Dysfunction ◽  
Motor Deficit ◽  
Middle Temporal Gyrus ◽  
Eigenvector Centrality ◽  
Middle Temporal ◽  
Mri Study

Background: Cerebral microinfarcts (CMIs) might cause measurable disruption to brain connections and are associated with cognitive decline, but the association between CMIs and motor impairment is still unclear. Objective: To assess the CMIs effect on motor function in vivo and explore the potential neuropathological mechanism based on graph-based network method. Methods: We identified 133 non-demented middle-aged and elderly participants who underwent MRI scanning, cognitive, and motor assessment. The short physical performance battery (SPPB) assessed motor function, including balance, walking speed, and chair stand. We grouped participants into 34 incident CMIs carriers and 99 non-CMIs carriers as controls, depending on diffusion-weighted imaging. Then we assessed the independent CMIs effects on motor function and explored neural mechanisms of CMIs on motor impairment via mapping of degree centrality (DC) and eigenvector centrality (EC). Results: CMIs carriers had worse motor function than non-carriers. Linear regression analyses showed that CMIs independently contributed to motor function. CMIs carriers had decreased EC in the precuneus, while increased DC and EC in the middle temporal gyrus and increased DC in the inferior frontal gyrus compared to controls (p < 0.05, corrected). Correlation analyses showed that EC of precuneus was related to SPPB (r = 0.25) and balance (r = 0.27); however, DC (r = –0.25) and EC (r = –0.25) of middle temporal gyrus was related with SPPB in all participants (p < 0.05, corrected). Conclusion: CMIs represent an independent risk factor for motor dysfunction. The relationship between CMIs and motor function may be attributed to suppression of functional hub region and compensatory activation of motor-related regions.

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 Neural Basis of Depression Related to a Dominant Right Hemisphere: A Resting-State fMRI Study

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mi Li ◽  
Hongpei Xu ◽  
Shengfu Lu
Keyword(s):  
Right Hemisphere ◽  
Inferior Frontal Gyrus ◽  
Middle Temporal Gyrus ◽  
Neural Basis ◽  
Middle Temporal ◽  
Middle Occipital Gyrus ◽  
The Right ◽  
Depressive Patients ◽  
The Brain ◽  
Left Middle

Background. In the past, studies on the lateralization of the left and right hemispheres of the brain suggested that depression is dominated by the right hemisphere of the brain, but the neural basis of this theory remains unclear. Method. Functional magnetic resonance imaging of the brain was performed in 22 depressive patients and 15 healthy controls. The differences in the mean values of the regional homogeneity (ReHo) of two groups were compared, and the low-frequency amplitudes of these differential brain regions were compared. Results. The results show that compared with healthy subjects, depressive patients had increased ReHo values in the right superior temporal gyrus, right middle temporal gyrus, left inferior temporal gyrus, left middle temporal gyrus, right middle frontal gyrus, triangular part of the right inferior frontal gyrus, orbital part of the right inferior frontal gyrus, right superior occipital gyrus, right middle occipital gyrus, bilateral anterior cingulate, and paracingulate gyri; reduced ReHo values were seen in the right fusiform gyrus, left middle occipital gyrus, left lingual gyrus, and left inferior parietal except in the supramarginal and angular gyri. Conclusions. The results show that regional homogeneity mainly occurs in the right brain, and the overall performance of the brain is such that right hemisphere synchronization is enhanced while left hemisphere synchronization is weakened. ReHo abnormalities in the resting state can predict abnormalities in individual neurological activities that reflect changes in the structure and function of the brain; abnormalities shown with this indicator are the neuronal basis for the phenomenon that the right hemisphere of the brain has a dominant effect on depression.

scholarly journals Considerations and Pitfalls in Selecting the Drug Vehicles for Evaluation of New Drug Candidates: Focus on in vivo Pharmaco-Toxicological Assays Based on the Rotarod Performance Test

2018 ◽  
Vol 21 ◽  
pp. 110-118 ◽  
Author(s):  
Mariana Matias ◽  
Samuel Silvestre ◽  
Amílcar Falcão ◽  
Gilberto Alves
Keyword(s):  
Performance Test ◽  
Motor Impairment ◽  
New Drugs ◽  
Motor Deficit ◽  
Early Evaluation ◽  
Rotarod Performance ◽  
Peg 400 ◽  
The Impact ◽  
Selection Of

Purpose - During the discovery and development of new drugs, compounds with low aqueous solubility pose special challenges in their pharmacological evaluation and, therefore, the selection of appropriate vehicles to administer the compounds of interest is determinant for the quality of the results generated during the in vivo non-clinical studies. This work aimed to evaluate the motor deficit (as a surrogate of neurotoxicity) of several administration/delivery vehicles through the rotarod performance test. Methods - Trained male CD-1 mice were intraperitoneally administered with the following vehicles: dimethyl sulfoxide (DMSO), aqueous sodium chloride (NaCl) 0.9%, aqueous carboxymethylcellulose (CMC) 0.5%, polyethylene glycol (PEG)-400, propylene glycol (PG), and solutions of these vehicles containing 5% and 10% DMSO. Results - It was observed that the aqueous vehicles (NaCl 0.9% and CMC 0.5%) did not affect the performance of the animals on the rod. On the other hand, a vehicle consisting solely of DMSO led to significant motor impairment and only a small improvement was recorded over time. Additionally, a strong neuromotor toxicity was observed in the early evaluation points of the experiment using vehicles constituted by PG and PEG-400 or by mixtures of PG/DMSO (5% and 10%) and PEG-400/DMSO (5% and 10%). Conclusion - This study provides useful data about the neurotoxicity inherent to several vehicles frequently used in non-clinical pharmaco-toxicological assays, aiming to draw especial attention to the need of a careful selection of drug vehicles in order to avoid the impact of such confounding variables on the accuracy of the results and in decision-making processes. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals The Shape of Things to Come in Speech Production: A Functional Magnetic Resonance Imaging Study of Visual Form Interference during Lexical Access

2019 ◽  
Vol 31 (6) ◽  
pp. 913-921 ◽  
Author(s):  
Hanna S. Gauvin ◽  
Katie L. McMahon ◽  
Marcus Meinzer ◽  
Greig I. de Zubicaray
Keyword(s):  
Speech Production ◽  
Language Production ◽  
Context Effects ◽  
Inferior Frontal Gyrus ◽  
Imaging Study ◽  
Middle Temporal Gyrus ◽  
Distractor Word ◽  
Lexical Selection ◽  
Middle Temporal ◽  
Visual Form

Studies of context effects in speech production have shown that semantic feature overlap produces interference in naming of categorically related objects. In neuroimaging studies, this semantic interference effect is consistently associated with involvement of left superior and middle temporal gyri. However, at least part of this effect has recently been shown to be attributable to visual form similarity, as categorically related objects typically share visual features. This fMRI study examined interference produced by visual form overlap in the absence of a category relation in a picture–word interference paradigm. Both visually similar and visually dissimilar distractors led to increased BOLD responses in the left inferior frontal gyrus compared with the congruent condition. Naming pictures in context with a distractor word denoting an object visually similar in form slowed RTs compared with unrelated words and was associated with reduced activity in the left posterior middle temporal gyrus. This area is reliably observed in lexical level processing during language production tasks. No significant differential activity was observed in areas typically engaged by early perceptual or conceptual feature level processing or in areas proposed to be engaged by postlexical language processes, suggesting that visual form interference does not arise from uncertainty or confusion during perceptual or conceptual identification or after lexical processing. We conclude that visual form interference has a lexical locus, consistent with the predictions of competitive lexical selection models.

scholarly journals Subjective Cognitive Decline Modifies the Relationship Between Cerebral Blood Flow and Memory Function in Cognitively Normal Older Adults

2017 ◽  
Vol 24 (3) ◽  
pp. 213-223 ◽  
Author(s):  
Chelsea C. Hays ◽  
Zvinka Z. Zlatar ◽  
Laura Campbell ◽  
M.J. Meloy ◽  
Christina E. Wierenga
Keyword(s):  
Cognitive Decline ◽  
Verbal Memory ◽  
Memory Performance ◽  
Inferior Frontal Gyrus ◽  
Memory Function ◽  
Posterior Cingulate Cortex ◽  
Middle Temporal Gyrus ◽  
Subjective Cognitive Decline ◽  
Cognitively Normal ◽  
Middle Temporal

AbstractObjectives: Subjective cognitive decline (SCD), or self-reported cognitive decline despite normal neuropsychological test performance, is a risk factor for objective cognitive decline and Alzheimer’s disease (AD). While brain mechanisms contributing to SCD are not well defined, studies show associations with vascular risk factors and altered cerebral blood flow (CBF), raising the hypothesis that those with SCD might be experiencing vascular dysregulation, or a disruption in the normal relationship between CBF and cognition. We examined whether the association between CBF and verbal memory performance differs between those with SCD (SCD+) and those without SCD (SCD-). Methods: Linear mixed-effects models were used to investigate whether the voxel-wise relationship between arterial spin labeling (ASL) MRI-measured CBF and verbal memory performance was modified by SCD among a group of 70 cognitively normal older adults (35 SCD+, 35 SCD-; mean age=72) matched on age, gender, and symptoms of depression. Results: Results indicated that the SCD- group exhibited positive associations between verbal memory and CBF within the posterior cingulate cortex, middle temporal gyrus, and inferior frontal gyrus, whereas the SCD+ group displayed negative associations between verbal memory and CBF within the posterior cingulate cortex, middle temporal gyrus, hippocampus, fusiform gyrus, and inferior frontal gyrus. Conclusions: Findings suggest that, while higher CBF is supportive of memory function in those without SCD, higher CBF may no longer support memory function in those presenting with SCD, perhaps reflecting neurovascular dysregulation. (JINS, 2018, 24, 213–223)

scholarly journals Supramodal Sentence Processing in the Human Brain: Fmri Evidence for the Influence of Syntactic Complexity in More Than 200 Participants

2019 ◽  
Author(s):  
Julia Uddén ◽  
Annika Hultén ◽  
Jan-Mathijs Schoffelen ◽  
Nietzsche Lam ◽  
Karin Harbusch ◽  
...  
Keyword(s):  
Language Processing ◽  
Sentence Processing ◽  
Parietal Lobe ◽  
Inferior Frontal Gyrus ◽  
Middle Temporal Gyrus ◽  
Syntactic Complexity ◽  
Input Modality ◽  
Middle Temporal ◽  
Left Posterior ◽  
Brain Fmri

ABSTRACTThis study investigated two questions. One is to which degree sentence processing beyond single words is independent of the input modality (speech vs. reading). The second question is which parts of the network recruited by both modalities is sensitive to syntactic complexity. These questions were investigated by having more than 200 participants read or listen to well-formed sentences or series of unconnected words. A largely left-hemisphere fronto-temporoparietal network was found to be supramodal in nature, i.e. independent of input modality. In addition, the left inferior frontal gyrus (LIFG) and the left posterior middle temporal gyrus (LpMTG) were most clearly associated with left-branching complexity. The left anterior middle temporal gyrus (LaMTG) showed the greatest sensitivity to sentences that differed in right-branching complexity. Moreover, activity in LIFG and LpMTG increased from sentence onset to end, in parallel with an increase of the left-branching complexity. While LIFG, bilateral anterior and posterior MTG and left inferior parietal lobe (LIPL) all contribute to the supramodal unification processes, the results suggest that these regions differ in their respective contributions to syntactic complexity related processing. The consequences of these findings for neurobiological models of language processing are discussed.

scholarly journals Myotonic dystrophy type 1: frequency of ophthalmologic findings

2016 ◽  
Vol 74 (3) ◽  
pp. 183-188 ◽  
Author(s):  
Karin Suzete Ikeda ◽  
Cristina Iwabe-Marchese ◽  
Marcondes Cavalcante França Jr ◽  
Anamarli Nucci ◽  
Keila Monteiro de Carvalho
Keyword(s):  
Myotonic Dystrophy ◽  
Motor Function ◽  
Motor Impairment ◽  
Laboratory Diagnosis ◽  
Motor Dysfunction ◽  
Ocular Motility ◽  
Myotonic Dystrophy Type 1 ◽  
Myotonic Dystrophy Type ◽  
Function Measure

ABSTRACT The purpose of the study was to evaluate the frequency of ophthalmologic abnormalities in a cohort of myotonic dystrophy type 1 (DM1) patients and to correlate them with motor function. We reviewed the pathophysiology of cataract and low intraocular pressure (IOP). Method Patients were included after clinical and laboratory diagnosis and after signed informed consent. They were evaluated by Motor Function Measure scale, Portuguese version (MFM-P) and ophthalmic protocol. Results We evaluated 42 patients aged 17 to 64 years (mean 40.7 ± 12.5), 22 of which were men. IOP (n = 41) was reduced in all but one. We found cataract or positivity for surgery in 38 (90.48%) and ptosis in 23 (54.76%). These signs but not IOP were significantly correlated with severity of motor dysfunction. Abnormalities in ocular motility and stereopsis were observed. Conclusion Cataract and ptosis are frequent in DM1 and associated to motor dysfunction. Reduced IOP is also common, but appears not to be related with motor impairment.

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 Voxel-Based Meta-Analysis of Gray Matter Abnormalities in Multiple System Atrophy

2020 ◽  
Vol 12 ◽  
Author(s):  
Junyu Lin ◽  
Xinran Xu ◽  
Yanbing Hou ◽  
Jing Yang ◽  
Huifang Shang
Keyword(s):  
Multiple System Atrophy ◽  
Gray Matter ◽  
Meta Analysis ◽  
Inferior Frontal Gyrus ◽  
Superior Temporal Gyrus ◽  
Middle Temporal Gyrus ◽  
Significant Heterogeneity ◽  
Middle Temporal ◽  
The Right ◽  
Complementary Analysis

Purpose: This study aimed to identify consistent gray matter volume (GMV) changes in the two subtypes of multiple system atrophy (MSA), including parkinsonism subtype (MSA-P), and cerebellar subtype (MSA-C), by conducting a voxel-wise meta-analysis of whole brain voxel-based morphometry (VBM) studies.Method: VBM studies comparing MSA-P or MSA-C and healthy controls (HCs) were systematically searched in the PubMed, Embase, and Web of Science published from 1974 to 20 October 2020. A quantitative meta-analysis of VBM studies on MSA-P or MSA-C was performed using the effect size-based signed differential mapping (ES-SDM) method separately. A complementary analysis was conducted using the Seed-based d Mapping with Permutation of Subject Images (SDM-PSI) method, which allows a familywise error rate (FWE) correction for multiple comparisons of the results, for further validation of the results.Results: Ten studies were included in the meta-analysis of MSA-P subtype, comprising 136 MSA-P patients and 211 HCs. Five studies were included in the meta-analysis of MSA-C subtype, comprising 89 MSA-C patients and 134 HCs. Cerebellum atrophy was detected in both MSA-P and MSA-C, whereas basal ganglia atrophy was only detected in MSA-P. Cerebral cortex atrophy was detected in both subtypes, with predominant impairment of the superior temporal gyrus, inferior frontal gyrus, temporal pole, insula, and amygdala in MSA-P and predominant impairment of the superior temporal gyrus, middle temporal gyrus, fusiform gyrus, and lingual gyrus in MSA-C. Most of these results survived the FWE correction in the complementary analysis, except for the bilateral amygdala and the left caudate nucleus in MSA-P, and the right superior temporal gyrus and the right middle temporal gyrus in MSA-C. These findings remained robust in the jackknife sensitivity analysis, and no significant heterogeneity was detected.Conclusion: A different pattern of brain atrophy between MSA-P and MSA-C detected in the current study was in line with clinical manifestations and provided the evidence of the pathophysiology of the two subtypes of MSA.

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