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1.
BMC Psychiatry ; 21(1): 415, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34416848

RESUMO

BACKGROUND: Magnetic resonance imaging (MRI) studies have found thalamic abnormalities in major depressive disorder (MDD). Although there are significant differences in the structure and function of the thalamus between MDD patients and healthy controls (HCs) at the group level, it is not clear whether the structural and functional features of the thalamus are suitable for use as diagnostic prediction aids at the individual level. Here, we were to test the predictive value of gray matter density (GMD), gray matter volume (GMV), amplitude of low-frequency fluctuations (ALFF), and fractional amplitude of low-frequency fluctuations (fALFF) in the thalamus using multivariate pattern analysis (MVPA). METHODS: Seventy-four MDD patients and 44 HC subjects were recruited. The Gaussian process classifier (GPC) was trained to separate MDD patients from HCs, Gaussian process regression (GPR) was trained to predict depression scores, and Multiple Kernel Learning (MKL) was applied to explore the contribution of each subregion of the thalamus. RESULTS: The primary findings were as follows: [1] The balanced accuracy of the GPC trained with thalamic GMD was 96.59% (P < 0.001). The accuracy of the GPC trained with thalamic GMV was 93.18% (P < 0.001). The correlation between Hamilton Depression Scale (HAMD) score targets and predictions in the GPR trained with GMD was 0.90 (P < 0.001, r2 = 0.82), and in the GPR trained with GMV, the correlation between HAMD score targets and predictions was 0.89 (P < 0.001, r2 = 0.79). [2] The models trained with ALFF and fALFF in the thalamus failed to discriminate MDD patients from HC participants. [3] The MKL model showed that the left lateral prefrontal thalamus, the right caudal temporal thalamus, and the right sensory thalamus contribute more to the diagnostic classification. CONCLUSIONS: The results suggested that GMD and GMV, but not functional indicators of the thalamus, have good potential for the individualized diagnosis of MDD. Furthermore, the thalamus shows the heterogeneity in the structural features of thalamic subregions for predicting MDD. To our knowledge, this is the first study to focus on the thalamus for the prediction of MDD using machine learning methods at the individual level.


Assuntos
Transtorno Depressivo Maior , Transtorno Depressivo Maior/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Análise Multivariada , Tálamo/diagnóstico por imagem
2.
Neuropsychologia ; 160: 107978, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34339716

RESUMO

Self-compassion is an important emotion regulation strategy predicting positive psychological health and fewer psychopathological problems, but little is known about its structural neural basis. In the current study, we investigated the neurostructural correlates of dispositional self-compassion and its components using voxel-based morphometry (VBM). We found that self-compassion was inversely correlated with gray matter volume (GMV) in the left dorsolateral prefrontal cortex (DLPFC), which was primarily driven by the reduced self-judgment component. We also found that the mindfulness component was associated with greater GMV in the dorsomedial prefrontal cortex/anterior cingulate cortex and the left supplementary motor area, while the isolation and the over-identification components were both correlated with greater GMV in the right inferior temporal gyrus, and over-identification additionally related to less GMV in visual areas. Our findings suggest that dispositional self-compassion and its components are associated with brain structure in regions involved in emotion regulation, self-referential and emotion processing, with implications for the cognitive and neural mechanisms of self-compassion as well as those underlying the effects of self-compassion on its health outcomes.


Assuntos
Empatia , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Substância Cinzenta/diagnóstico por imagem , Humanos
3.
Medicine (Baltimore) ; 100(33): e27001, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34414988

RESUMO

ABSTRACT: This study aimed to investigate evidence of gray matter brain lesions in multiple sclerosis (MS) patients by evaluating the resting state alpha rhythm of brain electrical activity.The study included 50 patients diagnosed with MS recruited from the MS clinic with 50 age and gender-matched control participants. The study investigated parameters of posterior dominant rhythm (PDR) in the electroencephalography (EEG) recordings including wave frequency and amplitude. Functional disability among the patients was evaluated according to the expanded disability status scale. Univariate statistical analysis was completed using one-way analysis of variance and t test with a P value of less than .05 to indicate statistical significance.Patients with MS had significantly lower PDR frequency and amplitude values compared to the controls (P value < .01) and 34% of the MS patients had a PDR frequency of less than 8.5 Hz. The PDR frequency was negatively associated with the level of functional disability among the patients (P value <.001) and 4% of the patients had abnormal epileptiform discharges.Background slowing of resting alpha rhythms and epileptiform discharges are suggestive of gray matter degeneration and may help in the prediction and follow-up of cortical damage and functional disabilities among MS patients. Therefore, electroencephalography monitoring of the PDR spectrum may serve as an alternative or complementary tool with other imaging techniques to detect and monitor cerebral cortical lesions.


Assuntos
Eletroencefalografia/estatística & dados numéricos , Substância Cinzenta/anormalidades , Esclerose Múltipla/complicações , Adulto , Estudos de Casos e Controles , Eletroencefalografia/métodos , Feminino , Substância Cinzenta/diagnóstico por imagem , Humanos , Iraque , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/fisiopatologia
4.
Medicine (Baltimore) ; 100(33): e26888, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34414943

RESUMO

ABSTRACT: To determine the prognostic risk factors of patients with acute epidural hematoma (AEDH), a scoring system was established based on gray-white matter ratio (GWR) and internal verification was performed.All patients with AEDH who underwent surgical treatment in Qinghai Provincial People's Hospital from January 2013 to June 2019 were continuously collected. The clinical and imaging data of the patients were collected. According to Glasgow Outcome Scale at 3 months after operation, the patients were divided into poor and good prognosis groups, respectively. The GWR value of the nonhematoma side was measured at the inner capsule area. Univariate and multivariate analyses were used. Independent predictors significantly related to the prognosis of AEDH were screened out and a nomogram was established based on these factors.A total of 170 cases were included in this study, the Glasgow Coma Score (severe and moderate), cerebral hernia, midline shift, preoperative GWR, postoperative GWR, hematoma thickness/midline shift, time from coma to surgery, and decompression of bone flap were the independent risk factors for predicting the poor prognosis of AEDH. Moreover, the prediction ability of nomogram was higher than any other independent predictive factors.The nomogram model established represents the most effective factor to predict the prognosis of operated AEDH. The scoring system is characterized by high accuracy, simplicity and feasibility, with a wide range of clinical application prospects.


Assuntos
Substância Cinzenta/diagnóstico por imagem , Hematoma Epidural Craniano/diagnóstico por imagem , Hematoma Epidural Craniano/cirurgia , Substância Branca/diagnóstico por imagem , Adulto , Feminino , Humanos , Masculino , Prognóstico
5.
Neuroimage Clin ; 31: 102775, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34375884

RESUMO

BACKGROUND: Current diagnostic criteria of HIV-associated neurocognitive disorders (HAND) rely on neuropsychological assessments. The aim of this study was to evaluate if gray matter volumes (GMV) can distinguish people with HAND, neurocognitively unimpaired people with HIV (unimpaired PWH), and uninfected controls using linear discriminant analyses. METHODS: A total of 231 participants, including 110 PWH and 121 uninfected controls, completed a neuropsychological assessment and an MRI protocol. Among PWH, HAND (n = 48) and unimpaired PWH (n = 62) designations were determined using the widely accepted Frascati criteria. We then assessed the extent to which GMV, corrected for intracranial volume, could accurately distinguish the three groups using linear discriminant analysis. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, area under the curve (AUC), and accuracy were computed for each model using the classification results based on GMV compared to the neuropsychological assessment. RESULTS: The best performing model was comprised of bilaterally combined GMV and was stratified by sex. Among males, sensitivity was 85.2% (95% CI: 66.3%-95.8%), specificity was 97.0% (95% CI: 91.6%-99.4%), and the AUC was 0.91 (95% CI: 0.83-0.99). Among females, sensitivity was 100.0% (95% CI: 83.9%-100.0%), specificity was 98.8% (95% CI: 93.4%-100.0%), and the AUC was 0.99 (95% CI: 0.98-1.00). CONCLUSIONS: GMV accurately discriminated HAND from unimpaired PWH and controls. Measures of GMV may be highly sensitive to HAND, and revisions to the Frascati criteria should consider including GMV in conjunction with a neuropsychological assessment to diagnose HAND.


Assuntos
Substância Cinzenta , Infecções por HIV , Córtex Cerebral , Feminino , Substância Cinzenta/diagnóstico por imagem , Infecções por HIV/complicações , Infecções por HIV/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos
6.
Alzheimers Res Ther ; 13(1): 138, 2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34389066

RESUMO

BACKGROUND: Changes in grey matter covariance networks have been reported in preclinical and clinical stages of Alzheimer's disease (AD) and have been associated with amyloid-ß (Aß) deposition and cognitive decline. However, the role of tau pathology on grey matter networks remains unclear. Based on previously reported associations between tau pathology, synaptic density and brain structural measures, tau-related connectivity changes across different stages of AD might be expected. We aimed to assess the relationship between tau aggregation and grey matter network alterations across the AD continuum. METHODS: We included 533 individuals (178 Aß-negative cognitively unimpaired (CU) subjects, 105 Aß-positive CU subjects, 122 Aß-positive patients with mild cognitive impairment, and 128 patients with AD dementia) from the BioFINDER-2 study. Single-subject grey matter networks were extracted from T1-weighted images and graph theory properties including degree, clustering coefficient, path length, and small world topology were calculated. Associations between tau positron emission tomography (PET) values and global and regional network measures were examined using linear regression models adjusted for age, sex, and total intracranial volume. Finally, we tested whether the association of tau pathology with cognitive performance was mediated by grey matter network disruptions. RESULTS: Across the whole sample, we found that higher tau load in the temporal meta-ROI was associated with significant changes in degree, clustering, path length, and small world values (all p < 0.001), indicative of a less optimal network organisation. Already in CU Aß-positive individuals associations between tau burden and lower clustering and path length were observed, whereas in advanced disease stages elevated tau pathology was progressively associated with more brain network abnormalities. Moreover, the association between higher tau load and lower cognitive performance was only partly mediated (9.3 to 9.5%) through small world topology. CONCLUSIONS: Our data suggest a close relationship between grey matter network disruptions and tau pathology in individuals with abnormal amyloid. This might reflect a reduced communication between neighbouring brain areas and an altered ability to integrate information from distributed brain regions with tau pathology, indicative of a more random network topology across different AD stages.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Doença de Alzheimer/diagnóstico por imagem , Peptídeos beta-Amiloides/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Disfunção Cognitiva/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/metabolismo , Humanos , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Proteínas tau/metabolismo
7.
Med Image Anal ; 72: 102123, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34214958

RESUMO

Structural and anatomical analyses of magnetic resonance imaging (MRI) data often require a reconstruction of the three-dimensional anatomy to a statistical shape model. Our prior work demonstrated the usefulness of tetrahedral spectral features for grey matter morphometry. However, most of the current methods provide a large number of descriptive shape features, but lack an unsupervised scheme to automatically extract a concise set of features with clear biological interpretations and that also carries strong statistical power. Here we introduce a new tetrahedral spectral feature-based Bayesian manifold learning framework for effective statistical analysis of grey matter morphology. We start by solving the technical issue of generating tetrahedral meshes which preserve the details of the grey matter geometry. We then derive explicit weak-form tetrahedral discretizations of the Hamiltonian operator (HO) and the Laplace-Beltrami operator (LBO). Next, the Schrödinger's equation is solved for constructing the scale-invariant wave kernel signature (SIWKS) as the shape descriptor. By solving the heat equation and utilizing the SIWKS, we design a morphometric Gaussian process (M-GP) regression framework and an active learning strategy to select landmarks as concrete shape descriptors. We evaluate the proposed system on publicly available data from the Alzheimers Disease Neuroimaging Initiative (ADNI), using subjects structural MRI covering the range from cognitively unimpaired (CU) to full blown Alzheimer's disease (AD). Our analyses suggest that the SIWKS and M-GP compare favorably with seven other baseline algorithms to obtain grey matter morphometry-based diagnoses. Our work may inspire more tetrahedral spectral feature-based Bayesian learning research in medical image analysis.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Doença de Alzheimer/diagnóstico por imagem , Teorema de Bayes , Encéfalo/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Neuroimagem
8.
Transl Psychiatry ; 11(1): 395, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34282121

RESUMO

Anhedonia is a core symptom of multiple psychiatric disorders and has been associated with alterations in brain structure. Genome-wide association studies suggest that anhedonia is heritable, with a polygenic architecture, but few studies have explored the association between genetic loading for anhedonia-indexed by polygenic risk scores for anhedonia (PRS-anhedonia)-and structural brain imaging phenotypes. Here, we investigated how anhedonia and PRS-anhedonia were associated with brain structure within the UK Biobank cohort. Brain measures (including total grey/white matter volumes, subcortical volumes, cortical thickness (CT) and white matter integrity) were analysed using linear mixed models in relation to anhedonia and PRS-anhedonia in 19,592 participants (9225 males; mean age = 62.6 years, SD = 7.44). We found that state anhedonia was significantly associated with reduced total grey matter volume (GMV); increased total white matter volume (WMV); smaller volumes in thalamus and nucleus accumbens; reduced CT within the paracentral cortex, the opercular part of inferior frontal gyrus, precentral cortex, insula and rostral anterior cingulate cortex; and poorer integrity of many white matter tracts. PRS-anhedonia was associated with reduced total GMV; increased total WMV; reduced white matter integrity; and reduced CT within the parahippocampal cortex, superior temporal gyrus and insula. Overall, both state anhedonia and PRS-anhedonia were associated with individual differences in multiple brain structures, including within reward-related circuits. These associations may represent vulnerability markers for psychopathology relevant to a range of psychiatric disorders.


Assuntos
Anedonia , Substância Branca , Bancos de Espécimes Biológicos , Encéfalo/diagnóstico por imagem , Estudo de Associação Genômica Ampla , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fenótipo , Reino Unido , Substância Branca/diagnóstico por imagem
9.
Asian J Psychiatr ; 63: 102752, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34274629

RESUMO

Microglial activation has been proposed to contribute to the pathogenesis of schizophrenia. The present study addressed the questions of whether microglial reactivity is involved in the course of schizophrenia and is associated with aging. Transmission electron microscopy and morphometry were applied to estimate microglial density and ultrastructural parameters in layer 5 of the prefrontal cortex (BA10) in postmortem 21 chronic schizophrenia and 20 healthy control cases. A significant increase in microglial density was found in the schizophrenia group (+20 %), in young group (≤50 y.o.), in shorter duration of disease (≤26 yrs.) group, in early age at onset of disease (≤ 21 y.o.) group as compared to controls (p < 0.05) and in young schizophrenia group as compared to both young and elderly (>50 y.o.) controls (p < 0.05). Volume fraction (Vv) of mitochondria was significantly lower and area of lipofuscin granules was significantly higher in young and elderly schizophrenia groups as compared to young and elderly controls. Vv of lipofuscin granules strongly positively correlated with age and duration of disease in the schizophrenia group. Vv and the number (N) of lipofuscin granules were higher in longer duration (>26 yrs.) group as compared to shorter duration group (p < 0.01). Vv and N of vacuoles were increased in longer duration group as compared to controls (p < 0.01). The study provides evidence for microgliosis associated with age, duration of disease and age at onset of disease, progressive dystrophy and accelerated aging of microglia in gray matter of the prefrontal cortex in schizophrenia.


Assuntos
Microglia , Esquizofrenia , Idoso , Córtex Cerebral , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Córtex Pré-Frontal/diagnóstico por imagem
10.
Neuropsychology ; 35(6): 643-655, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34292026

RESUMO

OBJECTIVE: Late-life changes in cognition and brain integrity are both highly multivariate, time-dependent processes that are essential for understanding cognitive aging and neurodegenerative disease outcomes. The present study seeks to identify a latent variable model capable of efficiently reducing a multitude of structural brain change magnetic resonance imaging (MRI) measurements into a smaller number of dimensions. We further seek to demonstrate the validity of this model by evaluating its ability to reproduce patterns of coordinated brain volume change and to explain the rate of cognitive decline over time. METHOD: We used longitudinal cognitive data and structural MRI scans, obtained from a diverse sample of 358 participants (Mage = 74.81, SD = 7.17), to implement latent variable models for measuring brain change and to estimate the effects of these brain change factors on cognitive decline. RESULTS: Results supported a bifactor model for brain change with four group factors (prefrontal, temporolimbic, medial temporal, and posterior association) and one general change factor (global atrophy). Atrophy in the global (ß = 0.434, SE = 0.070), temporolimbic (ß = 0.275, SE = 0.085), and medial temporal (ß = 0.240, SE = 0.085) factors were the strongest predictors of global cognitive decline. Overall, the brain change model explained 59% of the variance in global cognitive slope. CONCLUSIONS: The current results suggest that brain change across 27 bilateral regions of interest can be grouped into five change factors, three of which (global gray matter, temporolimbic, and medial temporal lobe atrophy) are strongly associated with cognitive decline. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Disfunção Cognitiva , Doenças Neurodegenerativas , Idoso , Atrofia/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Cognição , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/patologia , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Doenças Neurodegenerativas/patologia
11.
Neuroimage Clin ; 31: 102745, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34225020

RESUMO

Parkinson disease (PD) is characterized by motor deficits related to structural changes in the basal ganglia-thalamocortical circuits. However, it is still unclear the exact nature of the association between grey matter alterations and motor symptoms. Therefore, the aim of our investigation was to identify the subcortical modifications associated with motor symptoms of PD over time - adopting voxel-based morphometry (VBM) and automated volumetry methods. We selected fifty subjects with PD from the Parkinson's Progression Markers Initiative (PPMI) database, who performed an MRI session at two time points: at baseline (i.e. at maximum 2 years after clinical diagnosis of PD) and after 48 months. Motor symptoms were assessed using the part III of the Unified Parkinson's Disease Rating Scale at the two time points. Our VBM and volumetric analyses showed a general atrophy in all subcortical regions when comparing baseline with 48 months. These findings confirmed previous observations indicating a subcortical alteration over time in PD. Furthermore, our findings supported the idea that a reduced volume in the thalamus and an increased volume in pallidum may be related to the decline in motor skills. These structural modifications are in accordance with the functional model of the basal ganglia-thalamocortical circuits controlling movements. Moreover, VBM and volumetry provided partially overlapping results, suggesting that these methods might capture complementary aspects of brain degeneration in PD.


Assuntos
Doença de Parkinson , Substância Cinzenta/diagnóstico por imagem , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Testes de Estado Mental e Demência , Doença de Parkinson/diagnóstico por imagem
12.
Neuroimage Clin ; 31: 102729, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34271514

RESUMO

BACKGROUNDS: Although evidence suggests that the activity of the anterior cingulate cortex involves social cognition, there are inconsistent findings regarding the aberrant cingulate gray matter (GM) and scanty evidence about altered cortical thickness and white matter (WM) of cingulate in individuals with autism spectrum disorder (ASD). Evidence supports the association between the genetic variants of CNTNAP2 and altered brain connectivity. This study investigated the cingulate substructure and its association with social awareness deficits and the CNTNAP2 variants in individuals with ASD and typically-developing controls (TDC). METHODS: We assessed 118 individuals with ASD and 122 TDC with MRI and clinical evaluation. The GM, WM volumes and cortical thickness of the cingulate gyrus were compared between ASD and TDC based on fine parcellation. Five SNPs of the CNTNAP2 linked to ASD and brain structural abnormality were genotyped, and rs2710102, rs2538991, rs2710126 passed quality control filters. RESULTS: ASD individuals showed thinner cortical thickness in bilateral cingulate subregions than TDC without significant group differences in GM and WM volumes. The WM volume of the right anterior cingulate gyrus was correlated with social awareness deficits in ASD. The CNTNAP2 variant demonstrated a main effect on the WM volumes of the right middle cingulate gyrus. Besides, the CNTNAP2 variants interacted with ASD diagnosis and age on the cortical thickness of the left anterior middle cingulate cortex. CONCLUSIONS: Our findings suggest that aberrant cingulate structure in ASD might be associated with the social awareness deficits and genetic variants of the CNTNAP2. These novel findings need validation.


Assuntos
Transtorno do Espectro Autista , Substância Branca , Transtorno do Espectro Autista/diagnóstico por imagem , Transtorno do Espectro Autista/genética , Encéfalo , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Substância Branca/diagnóstico por imagem
13.
Neurosci Biobehav Rev ; 129: 269-281, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34256069

RESUMO

The high comorbidity of Major Depressive Disorder (MDD), Anxiety Disorders (ANX), and Posttraumatic Stress Disorder (PTSD) has hindered the study of their structural neural correlates. The authors analyzed specific and common grey matter volume (GMV) characteristics by comparing them with healthy controls (HC). The meta-analysis of voxel-based morphometry (VBM) studies showed unique GMV diminutions for each disorder (p < 0.05, corrected) and less robust smaller GMV across diagnostics (p < 0.01, uncorrected). Pairwise comparison between the disorders showed GMV differences in MDD versus ANX and in ANX versus PTSD. These results endorse the hypothesis that unique clinical features characterizing MDD, ANX, and PTSD are also reflected by disorder specific GMV correlates.


Assuntos
Transtorno Depressivo Maior , Transtornos de Estresse Pós-Traumáticos , Transtornos de Ansiedade , Encéfalo/diagnóstico por imagem , Depressão , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética
14.
J Neural Eng ; 18(4)2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34284361

RESUMO

Objective. White matter tissue takes up approximately 50% of the human brain volume and it is widely known as a messenger conducting information between areas of the central nervous system. However, the characteristics of white matter neural activity and whether white matter neural recordings can contribute to movement decoding are often ignored and still remain largely unknown. In this work, we make quantitative analyses to investigate these two important questions using invasive neural recordings.Approach. We recorded stereo-electroencephalography (SEEG) data from 32 human subjects during a visually-cued motor task, where SEEG recordings can tap into gray and white matter electrical activity simultaneously. Using the proximal tissue density method, we identified the location (i.e. gray or white matter) of each SEEG contact. Focusing on alpha oscillatory and high gamma activities, we compared the activation patterns between gray matter and white matter. Then, we evaluated the performance of such white matter activation in movement decoding.Main results. The results show that white matter also presents activation under the task, in a similar way with the gray matter but at a significantly lower amplitude. Additionally, this work also demonstrates that combing white matter neural activities together with that of gray matter significantly promotes the movement decoding accuracy than using gray matter signals only.Significance. Taking advantage of SEEG recordings from a large number of subjects, we reveal the response characteristics of white matter neural signals under the task and demonstrate its enhancing function in movement decoding. This study highlights the importance of taking white matter activities into consideration in further scientific research and translational applications.


Assuntos
Substância Branca , Córtex Cerebral , Eletroencefalografia , Substância Cinzenta/diagnóstico por imagem , Humanos , Movimento , Substância Branca/diagnóstico por imagem
15.
Transl Psychiatry ; 11(1): 365, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34226491

RESUMO

Myelin deficiency is commonly recognized as an important pathological feature of brain tissues in schizophrenia (SZ). In this pilot study, global myelin content abnormalities in white matter (WM) and gray matter (GM) of SZ patients were non-invasively investigated using a novel clinically-targeted quantitative myelin imaging technique, fast macromolecular proton fraction (MPF) mapping. MPF maps were obtained from 23 healthy subjects and 31 SZ patients using a clinical 1.5T magnetic resonance imaging (MRI) scanner. Mean MPF in WM and GM was compared between the healthy control subjects and SZ patients with positive and negative leading symptoms using the multivariate analysis of covariance. The SZ patients had significantly reduced MPF in GM (p < 0.001) and WM (p = 0.02) with the corresponding relative decrease of 5% and 3%, respectively. The effect sizes for the myelin content loss in SZ relative to the control group were 1.0 and 1.5 for WM and GM, respectively. The SZ patients with leading negative symptoms had significantly lower MPF in GM (p < 0.001) and WM (p = 0.003) as compared to the controls and showed a significant MPF decrease in WM (p = 0.03) relative to the patients with leading positive symptoms. MPF in WM significantly negatively correlated with the disease duration in SZ patients (Pearson's r = -0.51; p = 0.004). This study demonstrates that chronic SZ is characterized by global microscopic brain hypomyelination of both WM and GM, which is associated with the disease duration and negative symptoms. Myelin deficiency in SZ can be detected and quantified by the fast MPF mapping method.


Assuntos
Esquizofrenia , Substância Branca , Encéfalo/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Projetos Piloto , Prótons , Esquizofrenia/diagnóstico por imagem , Substância Branca/diagnóstico por imagem
16.
Neuroimage Clin ; 30: 102673, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34215145

RESUMO

BACKGROUND: While psychosis is a risk factor for violence, the majority of individuals who perpetrate aggression do not present psychotic symptoms. Pathological aggressive behavior is associated with brain gray matter differences, which, in turn, has shown a relationship with increased psychopathic traits. However, no study, to our knowledge, has ever investigated gray matter differences in forensic psychiatric patients with psychosis compared with incarcerated individuals without psychosis matched on levels of psychopathic traits. Here, we employed source-based morphometry (SBM) to investigate gray matter differences in these two populations. METHODS: We scanned 137 participants comprising two offender subgroups: 69, non-psychotic incarcerated offenders and 68, psychotic, forensic psychiatric patients. Groups showed no difference in age, race, ethnicity, handedness, and Hare Psychopathy Checklist-Revised scores. Source-based morphometry was utilized to identify spatially distinct sets of brain regions where gray matter volumes covaried between groups. SBM is a data-driven, multivariate technique that uses independent components analysis to categorize groups of voxels that display similar variance patterns (e.g., components) that are compared across groups. RESULTS: SBM identified four components that differed between groups. These findings indicated greater loading weights in the superior, transverse, and middle temporal gyrus and anterior cingulate in the non-psychotic versus psychotic group; greater loading weights in the basal ganglia in the psychotic versus non-psychotic group; greater loading weights in the frontal pole, precuneus, and visual cortex among psychotic versus non-psychotic offenders; and greater loading weights in the thalamus and parahippocampal gyrus in psychotic versus non-psychotic groups. CONCLUSIONS: Two different offender groups that perpetrate violence and show comparable levels of psychopathic traits evidenced different gray matter volumes. We suggest that future studies of violent offenders with psychosis take psychopathic traits into account to refine neural phenotypes.


Assuntos
Prisioneiros , Transtornos Psicóticos , Transtorno da Personalidade Antissocial/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Transtornos Psicóticos/diagnóstico por imagem
17.
Neuroimage Clin ; 30: 102675, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34215146

RESUMO

BACKGROUND: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease leading to damage of white matter (WM) and grey matter (GM). Magnetic resonance imaging (MRI) is the modality of choice to assess brain damage in MS, but there is an unmet need in MRI for achieving higher sensitivity and specificity to MS-related microstructural alterations in WM and GM. OBJECTIVE: To explore whether tensor-valued diffusion MRI (dMRI) can yield sensitive microstructural read-outs for focal demyelination in cerebral WM and deep GM (DGM). METHODS: Eight rats underwent L-α-Lysophosphatidylcholine (LPC) injections in the WM and striatum to introduce focal demyelination. Multimodal MRI was performed at 7 Tesla after 7 days. Tensor-valued dMRI was complemented by diffusion tensor imaging, quantitative MRI and proton magnetic resonance spectroscopy (MRS). RESULTS: Quantitative MRI and MRS confirmed that LPC injections caused inflammatory demyelinating lesions in WM and DGM. Tensor-valued dMRI illustrated a significant decline of microscopic fractional anisotropy (µFA) in both LPC-treated WM and DGM (P < 0.005) along with a marked increase of isotropic kurtosis (MKI) in DGM (P < 0.0001). CONCLUSION: Tensor-valued dMRI bears considerable potential for microstructural imaging in MS, suggesting a regional µFA decrease may be a sensitive indicator of MS lesions, while a regional MKI increase may be particularly sensitive in detecting DGM lesions of MS.


Assuntos
Esclerose Múltipla , Substância Branca , Animais , Anisotropia , Encéfalo/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Substância Cinzenta/diagnóstico por imagem , Esclerose Múltipla/diagnóstico por imagem , Ratos , Roedores , Substância Branca/diagnóstico por imagem
18.
Neuroimage Clin ; 30: 102683, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34215153

RESUMO

An interplay of early environmental and genetic risk factors with recent stressful life events (SLEs) in adulthood increases the risk for adverse mental health outcomes. The interaction of early risk and current SLEs on brain structure has hardly been investigated. Whole brain voxel-based morphometry analysis was performed in N = 786 (64.6% female, mean age = 33.39) healthy subjects to identify correlations of brain clusters with commonplace recent SLEs. Genetic and early environmental risk factors, operationalized as those for severe psychopathology (i.e., polygenic scores for neuroticism, childhood maltreatment, urban upbringing and paternal age) were assessed as modulators of the impact of SLEs on the brain. SLEs were negatively correlated with grey matter volume in the left medial orbitofrontal cortex (mOFC, FWE p = 0.003). This association was present for both, positive and negative, life events. Cognitive-emotional variables, i.e., neuroticism, perceived stress, trait anxiety, intelligence, and current depressive symptoms did not account for the SLE-mOFC association. Further, genetic and environmental risk factors were not correlated with grey matter volume in the left mOFC cluster and did not affect the association between SLEs and left mOFC grey matter volume. The orbitofrontal cortex has been implicated in stress-related psychopathology, particularly major depression in previous studies. We find that SLEs are associated with this area. Important early life risk factors do not interact with current SLEs on brain morphology in healthy subjects.


Assuntos
Transtorno Depressivo Maior , Acontecimentos que Mudam a Vida , Adulto , Transtornos de Ansiedade , Encéfalo/diagnóstico por imagem , Feminino , Substância Cinzenta/diagnóstico por imagem , Humanos , Masculino , Estresse Psicológico
19.
Nutrients ; 13(6)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34073949

RESUMO

Deficiency of vitamin B6 and vitamin B12, mostly in vegetarians, is found to be associated with depression and adverse neurological function. We investigated whether vitamin B6, B12, and folate have an effect on brain structure, especially among depressed people who follow a specific diet. The study sample comprised 9426 participants from the UK Biobank cohort with a mean age of 62.4 years. A generalized linear model controlling for age, sex, body mass index, ethnicity, town send deprivation index, educational qualification, smoking, and alcohol intake was used to test the association between study groups and structural brain volumes. Depression was more prevalent, and intake of vitamin B6 and B12 was lower among vegetarians, while non-vegetarians had a lower intake of folate. Overall, no significant association was observed between vitamin B6, B12, and folate intakes and both global and subcortical brain volumes among participants with depression. However, vitamin B12 intake was positively associated with right pallidum among non-depressed participants, and a significant interaction between vitamin B12 intake and depression status on the right pallidum was observed. Also, a significant interaction between folate intake and depression status on grey matter (GM) volume and left thalamus was observed. Upon diet stratification, folate intake is associated with total brain volume and GM volume among vegetarians with depression. Furthermore, no significant associations were observed for subcortical regions. Our findings suggest that dietary intake of vitamin B6 and B12 might have an effect on brain structure. Vegetarians, particularly those who suffer from depression may benefit from supplementing their diets with vitamins B6, B12, and folate to ensure brain health. Further studies, especially with a larger sample size and longitudinal design, are needed to confirm these findings.


Assuntos
Encéfalo/anatomia & histologia , Depressão/epidemiologia , Ácido Fólico/administração & dosagem , Vegetarianos/estatística & dados numéricos , Vitamina B 12/administração & dosagem , Vitamina B 6/administração & dosagem , Idoso , Encéfalo/diagnóstico por imagem , Dieta , Ingestão de Alimentos , Feminino , Deficiência de Ácido Fólico/epidemiologia , Substância Cinzenta/diagnóstico por imagem , Humanos , Modelos Lineares , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Reino Unido/epidemiologia , Deficiência de Vitamina B 12/epidemiologia , Deficiência de Vitamina B 6/epidemiologia
20.
J Affect Disord ; 292: 9-20, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34087634

RESUMO

BACKGROUND: Bipolar disorder (BD) has been linked to abnormalities in the communication and gray matter volume (GMV) of large-scale brain networks, as reflected by impaired resting-state functional connectivity (rs-FC) and aberrant voxel-based morphometry (VBM). However, identifying patterns of large-scale network abnormality in BD has been elusive. METHODS: Whole-brain seed-based rs-FC and VBM studies comparing individuals with BD and healthy controls (HCs) were retrieved from multiple databases. Multilevel kernel density analysis was used to identify brain networks in which BD was linked to hyper-connectivity or hypo-connectivity with each prior network and the overlap between dysconnectivity and GMV changes. RESULTS: Thirty-six seed-based rs-FC publications (1526 individuals with BD and 1578 HCs) and 70 VBM publications (2715 BD and 3044 HCs) were included in the meta-analysis. Our results showed that BD was characterized by hypo-connectivity within the default network (DN), hyper-connectivity within the affective network (AN), and ventral attention network (VAN) and hypo- and hyper-connectivity within the frontoparietal network (FN). Hyper-connectivity between-network of AN-DN, AN-FN, AN-VAN, AN-thalamus network (TN), VAN-TN, VAN-DN, VAN-FN, and TN-sensorimotor network were found. Hypo-connectivity between-network of FN and DN was observed. Decreased GMV was found in the insula, inferior frontal gyrus, and anterior cingulate cortex. LIMITATIONS: Differential weights in the number of included studies and sample size of FC and VBM might have a disproportionate influence on the meta-analytic results. CONCLUSIONS: These results suggest that BD is characterized by both structural and functional abnormalities of large-scale neurocognitive networks, especially in the DN, AN, VAN, FN, and TN.


Assuntos
Transtorno Bipolar , Transtorno Bipolar/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Córtex Pré-Frontal
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