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1.
Psychiatry Res Neuroimaging ; 335: 111715, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37716134

RESUMO

Post-traumatic stress disorder (PTSD) is one of the most common mental health disorders among Shidu parents. Identification of gray and white matter differences between persistence of PTSD (P-PTSD) and remission of PTSD (R-PTSD) is crucial to determine their prognosis. A total of 37 Shidu parents with PTSD were followed for five years. Surface-based morphometry and diffusion tensor imaging were carried out to analyze the differences in gray and white matter between P-PTSD and R-PTSD. Finally, 30 patients with PTSD were enrolled, including 12 with P-PTSD and 18 with R-PTSD. Compared with patients with R-PTSD, patients with P-PTSD exhibited lower fractional anisotropy (FA) in Cluster 1 (including body of the corpus callosum, superior longitudinal fasciculus, corticospinal tract) and Cluster 2 (including inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, splenium of the corpus callosum) in the left cerebral hemisphere and higher cortical thickness in the right lateral occipital cortex (LOC). In patients with P-PTSD, FA values of Cluster 2 were negatively correlated with cortical thickness of the right LOC. These results suggest that among Shidu parents, differences were observed in gray and white matter between P-PTSD and R-PTSD. Moreover, some certain gray and white matter abnormalities were often present simultaneously in P-PTSD.


Assuntos
Substância Cinzenta , Leucoaraiose , Transtornos de Estresse Pós-Traumáticos , Substância Branca , Humanos , Imagem de Tensor de Difusão/métodos , População do Leste Asiático , Pais , Transtornos de Estresse Pós-Traumáticos/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia
2.
Dev Cogn Neurosci ; 60: 101224, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36863188

RESUMO

Stuttering is a neurodevelopmental disorder affecting 5-8 % of preschool-age children, continuing into adulthood in 1 % of the population. The neural mechanisms underlying persistence and recovery from stuttering remain unclear and little information exists on neurodevelopmental anomalies in children who stutter (CWS) during preschool age, when stuttering symptoms typically first emerge. Here we present findings from the largest longitudinal study of childhood stuttering to date, comparing children with persistent stuttering (pCWS) and those who later recovered from stuttering (rCWS) with age-matched fluent peers, to examine the developmental trajectories of both gray matter volume (GMV) and white matter volume (WMV) using voxel-based morphometry. A total of 470 MRI scans were analyzed from 95 CWS (72 pCWS and 23 rCWS) and 95 fluent peers between 3 and 12 years of age. We examined overall group and group by age interactions in GMV and WMV in preschool age (3-5 years old) and school age (6-12 years old) CWS and controls, controlling for sex, IQ, intracranial volume, and socioeconomic status. The results provide broad support for a possible basal ganglia-thalamocortical (BGTC) network deficit starting in the earliest phases of the disorder and point to normalization or compensation of earlier occurring structural changes associated with stuttering recovery.


Assuntos
Gagueira , Substância Branca , Criança , Pré-Escolar , Humanos , Estudos Longitudinais , Substância Cinzenta/diagnóstico por imagem , Córtex Cerebral , Fala
3.
Artigo em Inglês | MEDLINE | ID: mdl-35123109

RESUMO

BACKGROUND: Much work has been dedicated to understanding the effects of adverse home environments on brain development. While the school social and learning environment plays a role in child development, little work has been done to investigate the impact of the school environment on the developing brain. The goal of the present study was to examine associations between the school environment, brain structure and connectivity, and mental health. METHODS: In this preregistered study we investigated these questions in a large sample of adolescents (9-10 years of age) from the Adolescent Brain Cognitive Development (ABCD) Study. We examined the association between school environment and gray matter (n = 10,435) and white matter (n = 10,770) structure and functional connectivity (n = 9528). We then investigated multivariate relationships between school-associated brain measures and mental health. RESULTS: School environment was associated with connectivity of the auditory and retrosplenial temporal network as well as of higher-order cognitive networks like the cingulo-opercular, default mode, ventral attention, and frontoparietal networks. Multivariate analyses revealed that connectivity of the cingulo-opercular and default mode networks was also associated with mental health. CONCLUSIONS: Findings shed light on the neural mechanisms through which favorable school environments may contribute to positive mental health outcomes in children. Our findings have implications for interventions targeted at promoting positive youth functioning through improving school environments.


Assuntos
Mapeamento Encefálico , Saúde Mental , Adolescente , Humanos , Criança , Imageamento por Ressonância Magnética , Encéfalo , Cognição
4.
Biol Trace Elem Res ; 201(2): 592-602, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35258774

RESUMO

The human neocortex has a cytoarchitecture composed of six layers with an intrinsic organization that relates to afferent and efferent pathways for a high functional specialization. Various histological, neurochemical, and connectional techniques have been used to study these cortical layers. Here, we explore the additional possibilities of swift ion beam and synchrotron radiation techniques to distinguish cellular layers based on the elemental distributions and areal density pattern in the human neocortex. Temporal cortex samples were obtained from two neurologically normal adult men (postmortem interval: 6-12 h). A cortical area of 500 × 500 µm2 was scanned by a 3 MeV proton beam for elemental composition and areal density measurements using particle induced x-ray emission (PIXE) and scanning transmission ion microscopy (STIM), respectively. Zinc showed higher values in cortical layers II and V, which needs a critical discussion. Furthermore, the areal density decreased in regions with a higher density of pyramidal neurons in layers III and V. Scanning transmission X-ray microscopy (STXM) revealed the cellular density with higher lateral resolution than STIM, but not enough to distinguish each cortical lamination border. Our data describe the practical results of these approaches employing both X-ray and ion-beam based techniques for the human cerebral cortex and its heterogeneous layers. These results add to the potential approaches and knowledge of the human neocortical gray matter in normal tissue to develop improvements and address further studies on pathological conditions.


Assuntos
Neocórtex , Masculino , Adulto , Humanos , Microscopia , Raios X , Imageamento por Ressonância Magnética , Contagem de Células
5.
Front Neurol ; 13: 690760, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35860485

RESUMO

Objective: Traumatic brain injury is one of the major causes of human olfactory dysfunction and leads to brain structure alterations, mainly in the cortical olfactory regions. Our study aimed to investigate volume changes in the gray matter (GM) and white matter (WM) in patients with post-traumatic anosmia and then to explore the relationship between GM volume and olfactory function. Methods: Ethics committee approved prospective studies which included 22 patients with post-traumatic anosmia and 18 age- and gender-matched healthy volunteers. Olfactory function was assessed using the Sniffin' Sticks. High-resolution 3-dimensional T1 MRIs of the participants were acquired on a 3T scanner and the data were collected for voxel-based morphometry (VBM) analysis. Furthermore, the GM and WM volumes of the whole brain regions were compared and correlated with olfactory function. Results: The analysis revealed significant GM volume reduction in the orbitofrontal cortex (OFC), gyrus rectus (GR), olfactory cortex, insula, parahippocampal, temporal pole, and cerebellum (all P < 0.001) in patients. Besides, WM volume loss was also found in the OFC, GR, and insula (all P < 0.001) in patients. All WM atrophy areas were connected to areas of GM volume loss spatially. Correlation analysis showed the olfactory scores were significantly positively correlated with the GM volume of the occipital cortex (P < 0.001, and P FWE < 0.05), while no significant correlation was found between the Sniffin' Sticks test scores and the WM volume in patients. Conclusion: The reduction of GM and WM volume in olfactory-related regions was responsible for olfactory dysfunction in post-traumatic patients. The occipital cortex may play a compensation mechanism to maintain the residual olfactory function. To our knowledge, we report here for the first time on white matter volume alterations specifically in post-traumatic patients with anosmia.

6.
Gerontology ; 68(2): 151-161, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33971654

RESUMO

BACKGROUND/AIMS: Walking speed (WS) is an objective measure of physical capacity and a modifiable risk factor of morbidity and mortality in the elderly. In this study, we (i) determined effects of 3-month supervised aerobic-strength training on WS, muscle strength, and habitual physical activity; (ii) evaluated capacity of long-term (21 months) training to sustain higher WS; and (iii) identified determinants of WS in the elderly. METHODS: Volunteers (F 48/M 14, 68.4 ± 7.1 years) completed either 3-month aerobic-strength (3 × 1 h/week, n = 48) or stretching (active control, n = 14) intervention (study A). Thirty-one individuals (F 24/M 7) from study A continued in supervised aerobic-strength training (2 × 1 h/week, 21 months) and 6 (F 5/M 1) became nonexercising controls. RESULTS: Three-month aerobic-strength training increased preferred and maximal WS (10-m walk test, p < 0.01), muscle strength (p < 0.01) and torque (p < 0.01) at knee extension, and 24-h habitual physical activity (p < 0.001), while stretching increased only preferred WS (p < 0.03). Effect of training on maximal WS was most prominent in individuals with baseline WS between 1.85 and 2.30 m·s-1. Maximal WS measured before intervention correlated negatively with age (r = -0.339, p = 0.007), but this correlation was weakened by the intervention (r = -0.238, p = 0.06). WS progressively increased within the first 9 months of aerobic-strength training (p < 0.001) and remained elevated during 21-month intervention (p < 0.01). Cerebellar gray matter volume (MRI) was positively associated with maximal (r = 0.54; p < 0.0001) but not preferred WS and explained >26% of its variability, while age had only minor effect. CONCLUSIONS: Supervised aerobic-strength training increased WS, strength, and dynamics of voluntary knee extension as well as habitual physical activity in older individuals. Favorable changes in WS were sustainable over the 21-month period by a lower dose of aerobic-strength training. Training effects on WS were not limited by age, and cerebellar cortex volume was the key determinant of WS.


Assuntos
Treinamento Resistido , Idoso , Exercício Físico/fisiologia , Humanos , Força Muscular , Torque , Caminhada/fisiologia , Velocidade de Caminhada
7.
Mech Ageing Dev ; 200: 111575, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34600936

RESUMO

Brain aging is a complex process that affects everything from the subcellular to the organ level, begins early in life, and accelerates with age. Morphologically, brain aging is primarily characterized by brain volume loss, cortical thinning, white matter degradation, loss of gyrification, and ventricular enlargement. Pathophysiologically, brain aging is associated with neuron cell shrinking, dendritic degeneration, demyelination, small vessel disease, metabolic slowing, microglial activation, and the formation of white matter lesions. In recent years, the mechanics community has demonstrated increasing interest in modeling the brain's (bio)mechanical behavior and uses constitutive modeling to predict shape changes of anatomically accurate finite element brain models in health and disease. Here, we pursue two objectives. First, we review existing imaging-based data on white and gray matter atrophy rates and organ-level aging patterns. This data is required to calibrate and validate constitutive brain models. Second, we review the most critical cell- and tissue-level aging mechanisms that drive white and gray matter changes. We focuse on aging mechanisms that ultimately manifest as organ-level shape changes based on the idea that the integration of imaging and mechanical modeling may help identify the tipping point when normal aging ends and pathological neurodegeneration begins.


Assuntos
Envelhecimento , Encéfalo , Senescência Celular/fisiologia , Envelhecimento/metabolismo , Envelhecimento/patologia , Atrofia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Encéfalo/patologia , Neuroimagem Funcional/métodos , Neuroimagem Funcional/tendências , Humanos , Modelos Biológicos
8.
J Mov Disord ; 14(2): 148-152, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34062648

RESUMO

OBJECTIVE: To determine the volume changes in gray and white matter during a long-term follow-up in patients suffering from pantothenate kinase-associated neurodegeneration (PKAN). METHODS: Magnetic resonance imaging was repeated in 13 patients and 14 age-matched controls after a mean interval of more than 7 years. T1-weighted sequences were evaluated by fully automated atlas-based volumetry, compared between groups and correlated with disease progression. RESULTS: The patients did not show generalized cerebral atrophy but did show a significantly faster volume reduction in the globus pallidus during follow-up (between -0.96% and -1.02% per year, p < 0.05 adjusted for false discovery rate) than controls, which was significantly related to the progression in their dystonia scores (p = 0.032). CONCLUSION: The volume loss in the globus pallidus over time-together with the accumulation of iron known as the "tiger's eye"-supports the pathophysiologic concept of this nucleus as a center of inhibition and its severe malfunction in PKAN.

9.
Quant Imaging Med Surg ; 11(6): 2224-2244, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34079697

RESUMO

BACKGROUND: Patients with Alzheimer disease (AD) and mild cognitive impairment (MCI) have high variability in brain tissue loss, making it difficult to use a disease-specific standard brain template. The objective of this study was to develop an AD-specific three-dimensional (3D) T1 brain tissue template and to evaluate the characteristics of the populations used to form the template. METHODS: We obtained 3D T1-weighted images from 294 individuals, including 101 AD, 96 amnestic MCI, and 97 cognitively normal (CN) elderly individuals, and segmented them into different brain tissues to generate AD-specific brain tissue templates. Demographic data and clinical outcome scores were compared between the three groups. Voxel-based analyses and regions-of-interest-based analyses were performed to compare gray matter volume (GMV) and white matter volume (WMV) between the three participant groups and to evaluate the relationship of GMV and WMV loss with age, years of education, and Mini-Mental State Examination (MMSE) scores. RESULTS: We created high-resolution AD-specific tissue probability maps (TPMs). In the AD and MCI groups, losses of both GMV and WMV were found with respect to the CN group in the hippocampus (F >44.60, P<0.001). GMV was lower with increasing age in all individuals in the left (r=-0.621, P<0.001) and right (r=-0.632, P<0.001) hippocampi. In the left hippocampus, GMV was positively correlated with years of education in the CN groups (r=0.345, P<0.001) but not in the MCI (r=0.223, P=0.0293) or AD (r=-0.021, P=0.835) groups. WMV of the corpus callosum was not significantly correlated with years of education in any of the three subject groups (r=0.035 and P=0.549 for left, r=0.013 and P=0.821 for right). In all individuals, GMV of the hippocampus was significantly correlated with MMSE scores (left, r=0.710 and P<0.001; right, r=0.680 and P<0.001), while WMV of the corpus callosum showed a weak correlation (left, r=0.142 and P=0.015; right, r=0.123 and P=0.035). CONCLUSIONS: A 3D, T1 brain tissue template was created using imaging data from CN, MCI, and AD participants considering the participants' age, sex, and years of education. Our disease-specific template can help evaluate brains to promote early diagnosis of MCI individuals and aid treatment of MCI and AD individuals.

10.
Dev Neurorehabil ; 24(4): 266-275, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33724900

RESUMO

Background: Childhood cancer survivors (Ccs) are at risk for cognitive late-effects, which might result from cortical alterations, even if cancer does not affect the brain. The study aimed to examine gray and white matter volume and its relationship to cognition. Methods: Forty-three Ccs of non-central nervous system cancers and 43 healthy controls, aged 7-16 years, were examined. Cognitive functions and fine motor coordination were assessed and T1-weighted images were collected for voxel-based morphometry. Results: Executive functions (p = .024, d = .31) were poorer in Ccs than controls, however still within the normal range. The volume of the amygdala (p = .011, ŋ2 = .117) and the striatum (p = .03, ŋ2 = .102) was reduced in Ccs. No significant structure-function correlations were found, neither in patients nor controls. Conclusion: Non-CNS childhood cancer and its treatment impacts on brain structures relevant to emotion processing.


Assuntos
Encéfalo/diagnóstico por imagem , Sobreviventes de Câncer , Cognição , Adolescente , Criança , Feminino , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Substância Branca/diagnóstico por imagem
11.
Microbiome ; 8(1): 44, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32238191

RESUMO

BACKGROUND: The impact of the gut microbiota on host physiology and behavior has been relatively well established. Whether changes in microbial composition affect brain structure and function is largely elusive, however. This is important as altered brain structure and function have been implicated in various neurodevelopmental disorders, like attention-deficit/hyperactivity disorder (ADHD). We hypothesized that gut microbiota of persons with and without ADHD, when transplanted into mice, would differentially modify brain function and/or structure. We investigated this by colonizing young, male, germ-free C57BL/6JOlaHsd mice with microbiota from individuals with and without ADHD. We generated and analyzed microbiome data, assessed brain structure and function by magnetic resonance imaging (MRI), and studied mouse behavior in a behavioral test battery. RESULTS: Principal coordinate analysis showed a clear separation of fecal microbiota of mice colonized with ADHD and control microbiota. With diffusion tensor imaging, we observed a decreased structural integrity of both white and gray matter regions (i.e., internal capsule, hippocampus) in mice that were colonized with ADHD microbiota. We also found significant correlations between white matter integrity and the differentially expressed microbiota. Mice colonized with ADHD microbiota additionally showed decreased resting-state functional MRI-based connectivity between right motor and right visual cortices. These regions, as well as the hippocampus and internal capsule, have previously been reported to be altered in several neurodevelopmental disorders. Furthermore, we also show that mice colonized with ADHD microbiota were more anxious in the open-field test. CONCLUSIONS: Taken together, we demonstrate that altered microbial composition could be a driver of altered brain structure and function and concomitant changes in the animals' behavior. These findings may help to understand the mechanisms through which the gut microbiota contributes to the pathobiology of neurodevelopmental disorders. Video abstract.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/microbiologia , Comportamento Animal , Encéfalo/fisiologia , Microbioma Gastrointestinal , Interações entre Hospedeiro e Microrganismos , Adulto , Animais , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Encéfalo/diagnóstico por imagem , Transplante de Microbiota Fecal , Vida Livre de Germes , Humanos , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transtornos do Neurodesenvolvimento/microbiologia , Adulto Jovem
12.
J Neurotrauma ; 37(11): 1342-1357, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-31830858

RESUMO

Traumatic brain injury (TBI) is a chronic pathology, inducing long-term deficits that remain understudied in pre-clinical studies. In this context, exploration, anxiety-like behavior, cognitive flexibility, and motor coordination were assessed until 5 and 10 months after an experimental TBI in the adult mouse, using two cohorts. In order to differentiate age, surgery, and remote gray and white matter lesions, three groups (unoperated, sham-operated, and TBI) were studied. TBI induced delayed motor coordination deficits at the pole test, 4.5 months after injury, that could be explained by gray and white matter damages in ipsilateral nigrostriatal structures (striatum, internal capsule) that were spreading to new structures between cohorts, at 5 versus 10 months after the injury. Further, TBI induced an enhanced exploratory behavior during stressful situations (active phase during actimetry test, object exploration in an open field), risk-taking behaviors in the elevated plus maze 5 months after injury, and a cognitive inflexibility in the Barnes maze that persisted until 9 months after the injury. These behavioral modifications could be related to the white and gray matter lesions observed in ipsi- and contralateral limbic structures (amygdala, hilus/cornu ammonis 4, hypothalamus, external capsule, corpus callosum, and cingular cortex) that were spreading to new structures between cohorts, at 5 months versus 10 months after the injury. The present study corroborates clinical findings on TBI and provides a relevant rodent chronic model which could help in validating pharmacological strategies against the chronic consequences of TBI.


Assuntos
Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/psicologia , Encéfalo/patologia , Comportamento Exploratório/fisiologia , Aprendizagem em Labirinto/fisiologia , Animais , Lesões Encefálicas Traumáticas/cirurgia , Seguimentos , Masculino , Camundongos , Fatores de Tempo
13.
Genes Brain Behav ; 18(1): e12475, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29566304

RESUMO

Oligodendrocyte gene expression is downregulated in stress-related neuropsychiatric disorders, including depression. In mice, chronic social stress (CSS) leads to depression-relevant changes in brain and emotional behavior, and the present study shows the involvement of oligodendrocytes in this model. In C57BL/6 (BL/6) mice, RNA-sequencing (RNA-Seq) was conducted with prefrontal cortex, amygdala and hippocampus from CSS and controls; a gene enrichment database for neurons, astrocytes and oligodendrocytes was used to identify cell origin of deregulated genes, and cell deconvolution was applied. To assess the potential causal contribution of reduced oligodendrocyte gene expression to CSS effects, mice heterozygous for the oligodendrocyte gene cyclic nucleotide phosphodiesterase (Cnp1) on a BL/6 background were studied; a 2 genotype (wildtype, Cnp1+/- ) × 2 environment (control, CSS) design was used to investigate effects on emotional behavior and amygdala microglia. In BL/6 mice, in prefrontal cortex and amygdala tissue comprising gray and white matter, CSS downregulated expression of multiple oligodendroycte genes encoding myelin and myelin-axon-integrity proteins, and cell deconvolution identified a lower proportion of oligodendrocytes in amygdala. Quantification of oligodendrocyte proteins in amygdala gray matter did not yield evidence for reduced translation, suggesting that CSS impacts primarily on white matter oligodendrocytes or the myelin transcriptome. In Cnp1 mice, social interaction was reduced by CSS in Cnp1+/- mice specifically; using ionized calcium-binding adaptor molecule 1 (IBA1) expression, microglia activity was increased additively by Cnp1+/- and CSS in amygdala gray and white matter. This study provides back-translational evidence that oligodendrocyte changes are relevant to the pathophysiology and potentially the treatment of stress-related neuropsychiatric disorders.


Assuntos
Oligodendroglia/metabolismo , Comportamento Social , Estresse Psicológico/genética , Transcriptoma , Tonsila do Cerebelo/metabolismo , Animais , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 1/genética , Nucleotídeo Cíclico Fosfodiesterase do Tipo 1/metabolismo , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Córtex Pré-Frontal/metabolismo , Estresse Psicológico/metabolismo
14.
J Magn Reson Imaging ; 48(5): 1217-1227, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29707834

RESUMO

BACKGROUND: Segmentation of the gray and white matter (GM, WM) of the human spinal cord in MRI images as well as the analysis of spinal cord diffusivity are challenging. When appropriately segmented, diffusion tensor imaging (DTI) of the spinal cord might be beneficial in the diagnosis and prognosis of several diseases. PURPOSE: To evaluate the applicability of a semiautomatic algorithm provided by ITK-SNAP in classification mode (CLASS) for segmenting cervical spinal cord GM, WM in MRI images and analyzing DTI parameters. STUDY TYPE: Prospective. SUBJECTS: Twenty healthy volunteers. SEQUENCES: 1.5T, turbo spin echo, fast field echo, single-shot echo planar imaging. ASSESSMENT: Three raters segmented the tissues by manual, CLASS, and atlas-based methods (Spinal Cord Toolbox, SCT) on T2 -weighted and DTI images. Masks were quantified by similarity and distance metrics, then analyzed for repeatability and mutual comparability. Masks created over T2 images were registered into diffusion space and fractional anisotropy (FA) values were statistically evaluated for dependency on method, rater, or tissue. STATISTICAL TESTS: t-test, analysis of variance (ANOVA), coefficient of variation, Dice coefficient, Hausdorff distance. RESULTS: CLASS segmentation reached better agreement with manual segmentation than did SCT (P < 0.001). Intra- and interobserver repeatability of SCT was better for GM and WM (both P < 0.001) but comparable with CLASS in entire spinal cord segmentation (P = 0.17 and P = 0.07, respectively). While FA values of whole spinal cord were not influenced by choice of segmentation method, both semiautomatic methods yielded lower FA values (P < 0.005) for GM than did the manual technique (mean differences 0.02 and 0.04 for SCT and CLASS, respectively). Repeatability of FA values for all methods was sufficient, with mostly less than 2% variance. DATA CONCLUSION: The presented semiautomatic method in combination with the proposed approach to data registration and analyses of spinal cord diffusivity can potentially be used as an alternative to atlas-based segmentation. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1217-1227.


Assuntos
Medula Cervical/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Imagem Ecoplanar , Substância Cinzenta/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Adulto , Algoritmos , Anisotropia , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Aprendizado de Máquina , Masculino , Variações Dependentes do Observador , Estudos Prospectivos , Traumatismos da Medula Espinal/diagnóstico por imagem , Adulto Jovem
15.
J Neurosci Res ; 96(8): 1353-1366, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29732581

RESUMO

Amyotrophic lateral sclerosis (ALS) is an adult onset neurodegenerative disease characterized by progressive motor neuron degeneration in the brain and spinal cord leading to muscle atrophy, paralysis, and death. Mitochondrial dysfunction is a major contributor to motor neuron degeneration associated with ALS progression. Mitochondrial abnormalities have been determined in spinal cords of animal disease models and ALS patients. However, molecular mechanisms leading to mitochondrial dysfunction in sporadic ALS (sALS) patients remain unclear. Also, segmental or regional variation in mitochondrial activity in the spinal cord has not been extensively examined in ALS. In our study, the activity of mitochondrial electron transport chain complex IV was examined in post-mortem gray and white matter of the cervical and lumbar spinal cords from male and female sALS patients and controls. Mitochondrial distribution and density in spinal cord motor neurons, lateral funiculus, and capillaries in gray and white matter were analyzed by immunohistochemistry. Results showed that complex IV activity was significantly decreased only in gray matter in both cervical and lumbar spinal cords from ALS patients. In ALS cervical and lumbar spinal cords, significantly increased mitochondrial density and altered distribution were observed in motor neurons, lateral funiculus, and cervical white matter capillaries. Discrete decreased complex IV activity in addition to changes in mitochondria distribution and density determined in the spinal cord in sALS patients are novel findings. These explicit mitochondrial defects in the spinal cord may contribute to ALS pathogenesis and should be considered in development of therapeutic approaches for this disease.


Assuntos
Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Medula Espinal/metabolismo , Medula Espinal/patologia , Adulto , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Substância Cinzenta/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Substância Branca/patologia
16.
Magn Reson Med ; 80(2): 452-461, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29344979

RESUMO

PURPOSE: The transverse relaxation times T2 of 17 metabolites in vivo at 3T is reported and region specific differences are addressed. METHODS: An echo-time series protocol was applied to one, two, or three volumes of interest with different fraction of white and gray matter including a total number of 106 healthy volunteers and acquiring a total number of 128 spectra. The data were fitted with the 2D fitting tool ProFit2, which included individual line shape modeling for all metabolites and allowed the T2 calculation of 28 moieties of 17 metabolites. RESULTS: The T2 of 10 metabolites and their moieties have been reported for the first time. Region specific T2 differences in white and gray matter enriched tissue occur in 16 of 17 metabolites examined including single resonance lines and coupled spin systems. CONCLUSION: The relaxation time T2 is regions specific and has to be considered when applying tissue composition correction for internal water referencing. Magn Reson Med 80:452-461, 2018. © 2018 International Society for Magnetic Resonance in Medicine.


Assuntos
Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/metabolismo , Imageamento por Ressonância Magnética/métodos , Substância Branca/diagnóstico por imagem , Substância Branca/metabolismo , Adulto , Algoritmos , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Razão Sinal-Ruído , Adulto Jovem
17.
Tissue Barriers ; 4(1): e1143544, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27141424

RESUMO

The brain microvascular network is comprised of capillaries, arterioles and venules, all of which retain - although to a different extent - blood-brain barrier (BBB) properties. Capillaries constitute the largest and tightest microvasculature. In contrast, venules have a looser junctional arrangement, while arterioles have a lower expression of P-gp. Development and maintenance of the BBB depends on the interaction of cerebral endothelial cells with pericytes and astrocytes, which are all heterogeneous in different regions of the central nervous system. At the level of circumventricular organs microvessels are permeable, containing fenestrations and discontinuous tight junctions. In addition, the blood-spinal cord barrier - where the number of pericytes is lower and expression of junctional proteins is reduced - is also more permeable than the BBB. However, much less is known about the cellular, molecular and functional differences among other regions of the brain. This review summarizes our current knowledge on the heterogeneity of the brain microvasculature.


Assuntos
Barreira Hematoencefálica/citologia , Animais , Astrócitos/citologia , Astrócitos/metabolismo , Barreira Hematoencefálica/metabolismo , Permeabilidade Capilar , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Humanos , Pericitos/citologia , Pericitos/metabolismo
18.
Eur J Med Genet ; 59(2): 70-4, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26721324

RESUMO

Early Infantile Epileptic Encephalopathy (EIEE) presents shortly after birth with frequent, severe seizures, a burst-suppression EEG pattern, and progressive disturbance of cerebral function. We present a case of EIEE associated with a de novo missense variant in ZEB2. Heterozygous truncating mutations or deletions in ZEB2 are known to cause Mowat-Wilson syndrome (MWS), which is characterized by seizures with onset in the second year of life, distinctive dysmorphic facial features and malformations that were absent in this patient. This unique case expands the range of phenotypes associated with variants in ZEB2 and indicates that this gene should be included in the molecular investigation of EIEE cases.


Assuntos
Síndrome de Aicardi/genética , Doença de Hirschsprung/genética , Proteínas de Homeodomínio/genética , Deficiência Intelectual/genética , Microcefalia/genética , Proteínas Repressoras/genética , Espasmos Infantis/genética , Síndrome de Aicardi/diagnóstico , Síndrome de Aicardi/fisiopatologia , Análise Mutacional de DNA , Eletroencefalografia , Exoma , Fácies , Doença de Hirschsprung/diagnóstico , Humanos , Recém-Nascido , Deficiência Intelectual/diagnóstico , Microcefalia/diagnóstico , Espasmos Infantis/diagnóstico , Espasmos Infantis/fisiopatologia , Homeobox 2 de Ligação a E-box com Dedos de Zinco
19.
Artigo em Inglês | MEDLINE | ID: mdl-28620654

RESUMO

The study of how the human brain develops has always been a challenge and an interest to the scientific community. In recent years, new evidence has suggested that many neuropsychiatric disorders may originate from aberrations early in development. This discovery necessitates the application of methodologies that make possible the investigation of human brain development in vivo and across the lifespan. In this commentary, we present evidence that the advent of structural neuroimaging has specifically and significantly contributed critical information about the developmental trajectories of postnatal human brain development that would otherwise not have been possible. We believe that this is particularly relevant to present day research as it has become increasingly clear that growth trajectories within the brain might serve as an endophenotype for a number of factors, ranging from IQ to psychiatric illness. We highlight seminal early works that helped to jumpstart the field of developmental neuroimaging and which inspired incredible new advances in neuroimaging methodologies that are being developed and applied in the field today.

20.
Cereb Cortex ; 25(9): 2854-62, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24770710

RESUMO

Focal cortical dysplasia (FCD) is a malformation of cortical development that is associated with high rates of cognitive morbidity. However, the degree to which specific irregularities of dysplastic tissue directly impact cognition remains unknown. This study investigates the relationship between blurring of the cortical gray and white matter boundary on magnetic resonance imaging (MRI) and global cognitive abilities in FCD. Gray-white blurring (GWB) is quantified by sampling the non-normalized T1 image intensity contrast above and below the gray and white matter interface along the cortical mantle. Spherical averaging is used to compare resulting GWB for patients with histopathologically verified FCD with matched controls. Whole-brain correlational analyses are used to investigate the relationship between blurring and general cognitive abilities, controlling for epilepsy duration. Results show that cognitive performance is reduced in patients with FCD relative to controls. Patients show increased GWB in bilateral temporal, parietal, and frontal regions. Furthermore, increased GWB in these regions is linearly related to decreased cognition and mediates group differences in cognitive performance. These findings demonstrate that GWB is a marker of reduced cognitive efficiency in FCD that can potentially be used to probe general and domain-specific cognitive functions in other neurological disorders.


Assuntos
Transtornos Cognitivos/etiologia , Substância Cinzenta/patologia , Malformações do Desenvolvimento Cortical/complicações , Malformações do Desenvolvimento Cortical/patologia , Substância Branca/patologia , Adolescente , Adulto , Córtex Cerebral/patologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Malformações do Desenvolvimento Cortical/classificação , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
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