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Connectivity driven registration of magnetic resonance images of the human brainPetrovic, Aleksandar January 2010 (has links)
Image registration methods underpin many analysis techniques in neuroimaging. They are essential in group studies when images of different individuals or different modalities need to be brought into a common reference frame. This thesis explores the potential of brain connectivity- driven alignment and develops surface registration techniques for magnetic resonance imaging (MRI), which is a noninvasive neuroimaging tool for probing function and structure of the human brain. The first part of this work develops a novel surface registration framework, based on free mesh deformations, which aligns cortical and subcortical surfaces by matching structural connectivity patterns derived using probabilistic tractography (diffusion-weighted MRI). Structural, i.e. white matter, connectivity is a good predictor of functional specialisation and structural connectivity-driven registration can therefore be expected to enhance the alignment of functionally homologous areas across subjects. The second part validates developed methods for cortical surfaces. Resting State Networks are used in an innovative way to delineate several functionally distinct regions, which were then used to quantify connectivity-driven registration performance by measuring the inter- subject overlap before and after registration. Consequently, the proposed method is assessed using an independent imaging modality and the results are compared to results from state-of-the-art cortical geometry-driven surface registration methods. A connectivity-driven registration pipeline is also developed for, and applied to, the surfaces of subcortical structures such as the thalamus. It is carefully validated on a set of artificial test examples and compared to another novel surface registration paradigm based on spherical wavelets. The proposed registration pipeline is then used to explore the differences in the alignment of two groups of subjects, healthy controls and Alzheimer's disease patients, to a common template. Finally, we propose how functional connectivity can be used instead of structural connectivity for driving registrations, as well as how the surface-based framework can be extended to a volumetric one. Apart from providing the benefits such as the improved functional alignment, we hope that the research conducted in this thesis will also represent the basis for the development of templates of structural and functional brain connectivity.
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La maladie d’Alzheimer comme syndrome de déconnexion et son impact sur le système du langageMontembeault, Maxime 08 1900 (has links)
No description available.
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Vliv výběru souřadnic regionů na výsledky dynamického kauzálního modelování / Influence of region coordinates selection on dynamic causal modelling resultsKlímová, Jana January 2013 (has links)
This thesis deals with functional magnetic resonance imaging (fMRI), in particular with dynamic causal modelling (DCM) as one of the methods for effective brain connectivity analysis. It has been studied the effect of signal coordinates selection, which was used as an input of DCM analysis, on its results based on simulated data testing. For this purpose, a data simulator has been created and described in this thesis. Furthermore, the methodology of testing the influence of the coordinates selection on DCM results has been reported. The coordinates shift rate has been simulated by adding appropriate levels of various types of noise signals to the BOLD signal. Consequently, the data has been analyzed by DCM. The program has been supplemented by a graphical user interface. To determine behaviour of the model, Monte Carlo simulations have been applied. Results in the form of dependence of incorrectly estimated connections between brain areas on the level of the noise signals have been processed and discussed.
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Déconstruire l'hétérogénéité des systèmes neurocognitifs sous-jacents aux comportements antisociaux : de l'analyse développementale aux corrélats neurobiologiquesDugré, Jules 08 1900 (has links)
Contexte. L’étiologie des comportements antisociaux est encore mal comprise. La population d’individus commettant ce type de comportements est hautement hétérogène, suggérant ainsi que plusieurs mécanismes biopsychosociaux pourraient augmenter ou réduire le risque de délinquance au cours du développement humain. Objectif. L’objectif principal de cette thèse est d’identifier ces mécanismes sous-jacents à la délinquance, par l’entremise de quatre méthodes scientifiques distinctes, mais complémentaires : les analyses de trajectoires développementales, l’activité cérébrale induite par une tâche, la connectivité cérébrale au repos ainsi que l’étude des lésions cérébrales. Méthodologie. Afin d’atteindre cet objectif, une première étude a été réalisée en réanalysant les données de l’Étude Longitudinale du Développement des Enfants du Québec (n=1309). Par l’entremise de modèles de trajectoires par classes latentes, cette étude visait à identifier des sous-groupes de jeunes présentant des trajectoires développementales de traits psychologiques (c.-à-d., l’insensibilité émotionnelle, les traits anxio-dépressifs, l’irritabilité et les traits d’hyperactivité/impulsivité) à risque de comportements antisociaux à l’enfance et l’adolescence. Par ailleurs, deux méta-analyses portant sur des études d’activation cérébrale (71 et 147 études) ont été réalisées afin d’identifier les principales altérations de l’activité cérébrale sous-jacent à différents domaines neurocognitifs, ainsi que leur similarité avec d’autres problématiques psychiatriques. De plus, une troisième méta-analyse (18 études) a été accomplie afin d’étudier si les individus antisociaux présentaient des déficits lors de la connectivité cérébrale au repos. De manière à combler les limites de la littérature sous-jacente à la connectivité cérébrale au repos des individus antisociaux, une étude transversale a été effectuée sur 1,416 enfants et adolescents issue Healthy Brain Network aux États-Unis. Outre l’objectif de valider les résultats de la méta-analyse précédente, cette étude a été conçue de manière à mieux comprendre le rôle de l’interaction entre des systèmes neurobiologiques dans l’explication des comportements antisociaux. Finalement, une récente revue de la littérature scientifique produite par des chercheurs américains a permis d’identifier 17 cas dans lesquels des lésions au cerveau étaient temporellement liés à l’émergence de comportements antisociaux. Grâce à une reconstruction des images de lesdites lésions, des analyses de coactivation méta- analytique ont été conduites afin de récréer les réseaux neurobiologiques altérés qui seraient possiblement à l’origine de de gestes délinquants. Résultats. Les résultats ont soutenu l’importance des traits d’insensibilité émotionnelle dans l’explication du risque de délinquance, et aussi montré que l’interaction développementale entre les traits psychologiques augmentait jusqu’à 10 fois le risque de comportements antisociaux à l’enfance. Sur une base neurobiologique, les résultats ont révélé que les personnes ayant commis des gestes délinquants rapporteraient d’importants déficits dans les régions cérébrales impliquées dans le contrôle cognitif, la réponse à une menace et les cognitions sociales. En comparaison avec le trouble du déficit de l’attention avec hyperactivité et les troubles anxieux et dépressifs, le trouble des conduites serait associé à un dysfonctionnement commun de régions cérébrales impliquées dans le contrôle des émotions et du système somato-moteur. Par ailleurs, les résultats indiquent que la population étudiée serait principalement caractérisée par une dysconnectivité fonctionnelle entre les réseaux socioaffectifse et attentionnels, mais aussi entre les systèmes somato-moteurs, attentionnels et ceux impliqués dans la détection de stimuli saillants. Finalement, les lésions cérébrales pourraient causer des comportements délinquants par l’entremise de trois mécanismes neurobiologiques, notamment par une défaillance du réseau de la récompense (lobe frontal), du réseau impliqué dans le traitement des émotions négatives (lobe temporal) ainsi que la reconnaissance émotionnelle faciale (amygdale). Conclusions. Les résultats des travaux présentés dans cette thèse soutiennent l’importance de mieux comprendre l’hétérogénéité de domaines neurocognitifs dans l’explication des comportements délinquants. D’une part, ceux-ci soulignent l’importance des systèmes neurobiologiques à valence négative (associés à l’anxiété et l’irritabilité), aux systèmes cognitifs (associés à l’hyperactivité/impulsivité et à l’inattention) ainsi qu’aux processus sociaux (associés à l’insensibilité émotionnelle). D’autre part, les résultats suggèrent un rôle limité des systèmes de récompense, mais un rôle prépondérant du système sensorimoteur (associé à l’action et au contrôle des mouvements). La présente thèse offre une perspective novatrice et exhaustive sur l’hétérogénéité neurocognitive sous-jacente à la délinquance. Or, la variabilité interindividuelle des systèmes neurobiologiques étudiés dans cette thèse reste à être identifiée, de manière à découvrir des cibles thérapeutiques prometteuses pour réduire le risque de délinquance. / Background. The etiology of antisocial behaviors remains largely misunderstood. Antisocial population is characterized as highly heterogeneous, therefore indicating that several biopsychosocial mechanisms may increase or reduce the risk for delinquency during human development. Aim. The principal aim of this thesis is to identify these mechanisms underlying delinquent behaviors through different yet complementary method: developmental trajectories, task-based brain activity, brain connectivity at rest as well as the study of brain lesions. Methodology. To do so, a first study was conducted by reanalyzing cohort data from the Quebec Longitudinal Study of Child Development (n=1,309). Latent growth curve models allowed to identify subgroups of children exhibiting developmental trajectories of psychological traits (i.e., callous-unemotional traits, anxio-depressive traits, irritability and hyperactivity/impulsivity) that are at risk for antisocial behaviors during childhood and adolescence. Also, two meta-analyses of neuroimaging studies (71 and 147 studies) were carried out to highlight main deficits in brain activity underlying distinct neurocognitive systems as well as their similarity with other psychiatric disorders. Moreover, a third meta-analysis (18 studies) is presented to better understand whether antisocial subjects may exhibit brain connectivity at rest. In order to overcome limitations of past studies examining resting-state functional connectivity, a cross-sectional study was performed on 1,416 children and adolescents derived from the Healthy Brain Network in the United States. Additionnally to examine reliability of meta-analytic findings, this study was conducted in order to better understand the role of the interaction between neurobiological systems in our understanding of antisocial behaviors. Finally, a recent literature review carried out by American researchers highlighted 17 cases during which focal brain lesions were temporally associated with emergence of antisocial behaviors. By reconstructing images of these brain lesions, meta-analytic coactivation modelling was conducted in order to recreate neurobiological systems which would possibly be the origins of delinquent acts. Results. The results observed in this thesis support the crucial role of callous- unemotional traits in our understanding of the risk for delinquency, but also suggest that the developmental interaction between psychological markers increases up to 10 times this risk. On a neurobiological ground, results revealed that individuals that have committed antisocial behaviors were mainly characterized by dysfunctions in brain regions involved in cognitive control, threat detection as well as social cognition. In comparison to attention-deficit/hyperactivity disorder and anxiety and depressive disorders, conduct disorder was similarly associated with dysfunction in regions related to emotion regulation and somatomotor functions. Moreover, the results suggest that antisocial population may be characterized by dysconnectivity between socio-affective and attentional processes and between somatomotor and attentional processes as well as those involved in salient detection mechanism. Finally, brain lesions may cause antisocial behaviors by three neurobiological mechanisms, notably by disrupting the reward network (frontal lesions), the network involved in negative emotion processing (temporal lesions) and the emotional face processing (amygdala lesions). Conclusions. The results of the work presented in this thesis support the importance of studying the heterogeneity in neurocognitive systems for our understanding of antisocial behaviors. On the one hand, these results highlight the role of neurobiological systems of negative valence (related to anxiety and irritability), cognitive systems (related to hyperactivity/impulsivity and inattention) and social cognition (related to callous-unemotional traits). On the other hand, the results underline the limited contribution of positive valence system, but a prominent role of sensorimotor system (related to action and motor control). The current thesis offers a novel and exhaustive perspective on the heterogeneity of neurocognitive systems underlying delinquent behaviors. The interindividual variability of these systems is yet to be unveiled in order to uncover promising targets for treatment in a hopeful aim to reduce risk for delinquency.
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The connectivity fingerprints of the frontal eye field and the inferior frontal junctionBedini, Marco 17 May 2023 (has links)
Within the prefrontal cortex, the frontal eye field (FEF) and the inferior frontal junction (IFJ) are crucial regions that mediate attention, working memory, and cognitive control functions. I comprehensively reviewed the neuroimaging evidence on these regions, suggesting that they are specialized in the control of spatial versus non-spatial visual processing, respectively, and hypothesized that their connectivity fingerprints might underlie these roles. To accurately infer the localization of these regions in standard space, I carried out an activation likelihood estimation (ALE) fMRI meta-analysis using tasks that reliably engage these regions. Prosaccade and antisaccade tasks were included in the FEF sample, whereas oddball/attention, n-back, Stroop and task-switching experiments were included in the IFJ sample (n = 35 and 32, respectively). The ALE technique revealed the strongest convergence of activations at the junctions of the superior precentral sulcus and superior frontal sulcus for the FEF, and the inferior precentral sulcus and inferior frontal sulcus for the IFJ. I employed the resulting ALE peaks to perform a meta-analytic connectivity modeling analysis to
uncover their whole-brain fMRI coactivations and decoded these patterns to infer significant associations with behavioral domains. The ALE peaks from a subsample of the previous meta-analysis were used to analyze 3T diffusion MRI data released by the Human Connectome Project from 56 unrelated subjects. Using a surface-based probabilistic tractography approach, I tracked streamlines ipsilaterally from the FEF and IFJ to regions of the dorsal and ventral visual streams on the native white matter surface parcellated using the atlas by Glasser et al. (2016). By contrasting their connectivity likelihood, I found predominant structural connectivity from FEF to regions of the dorsal visual stream (particularly in the left hemisphere) compared to the IFJ, and conversely, predominant structural connectivity from the IFJ to regions of the ventral visual stream compared to the FEF. These results were replicated when accounting for the
distance between FEF, IFJ, and the target regions. The connectivity fingerprints of the FEF and IFJ provide converging evidence of their specialization in the control of spatial vs non-spatial processing, which is mediated by long-range white matter association pathways. The results presented in this dissertation overall support the view that the two-visual stream architecture extends to the human prefrontal cortex, as was originally hypothesized in the macaque based on tract tracing and neurophysiological evidence.
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Dysconnectivité cérébrale fonctionnelle dans la schizophrénie : optimisation d'une intervention par neuromodulation pour réduire des symptômes cognitifsGrot, Stéphanie 12 1900 (has links)
La schizophrénie est un trouble de santé mentale sévère, caractérisée par des altérations neurobiologiques marquées. Un biomarqueur notoire de ce trouble est la dysconnectivité cérébrale fonctionnelle, détectée grâce à l’imagerie par résonance magnétique fonctionnelle. Celle-ci se retrouve principalement au niveau des réseaux neurocognitifs qui sous-tendent les fonctions cérébrales supérieures. Toutefois, les altérations de connectivité fonctionnelle cérébrale ne sont pas uniques à la schizophrénie, elles sont également retrouvées dans plusieurs autres troubles de santé mentale. Le premier objectif de cette thèse doctorale est d’effectuer une méta-analyse sur la dysconnectivité cérébrale fonctionnelle à l’état de repos pour dissocier les altérations spécifiques à la schizophrénie de celles qui sont communes aux troubles de l’humeur. Ce projet novateur basé sur l’extraction de labels neuroanatomiques inclut 428 articles scientifiques. Les résultats confirment des altérations transdiagnostiques des réseaux neurocognitifs et soulignent une dysconnectivité spécifique des réseaux sensorimoteurs dans la schizophrénie.
Parmi les altérations des réseaux neurocognitifs, une hyperconnectivité entre le réseau central exécutif (REC) et le réseau du mode par défaut (RMD) est associée à des déficits de mémoire de travail dans la schizophrénie, c’est-à-dire à des difficultés de mémorisation et de manipulation d’informations à court terme. Actuellement, aucun traitement efficace n’existe contre ces déficits. La stimulation magnétique transcrânienne (SMT), déjà approuvée comme traitement dans la dépression, est une piste de thérapie prometteuse. Elle agit en modulant spécifiquement les réseaux de connectivité dysfonctionnels. Jusqu’à présent, les effets de l'application de la SMT pour diminuer les déficits de mémoire de travail dans la schizophrénie sont mitigés. Une explication potentielle s’oriente vers la position de la cible de stimulation sur le cortex qui est standardisée et ne prend pas en compte l'importante variabilité interindividuelle dans l'organisation spatiale des réseaux de connectivité fonctionnelle. D'autres paramètres méthodologiques comme l’intensité de stimulation ont aussi un impact sur l’effet de la stimulation. Le second projet de cette thèse consiste à réaliser une étude rétrospective chez les sujets sains afin de confirmer l'importance de cibler spécifiquement le REC par la SMT pour induire une modulation fonctionnelle de celui-ci en fonction de l’intensité de stimulation. Nos résultats montrent que la stimulation spécifique du REC induit une diminution de la connectivité entre le REC et le RMD pour des intensités de stimulation plus faibles. Finalement, le troisième projet de cette thèse a pour objectif d'examiner prospectivement, dans la schizophrénie, l’impact d'une SMT personnalisée par rapport à une SMT standard sur la connectivité fonctionnelle à l’état de repos et les performances de mémoire de travail. La cible de la SMT personnalisée a été définie selon les patrons de connectivité individualisée des participants. L’analyse des données a mis en évidence une instabilité prononcée des réseaux de connectivité qui ne nous a pas permis de conclure quant à l’avantage d’une cible personnalisée pour diminuer l’hyperconnectivité entre REC et RMD et les déficits de mémoire de travail dans la schizophrénie. Toutefois, une relation avec la force de la connectivité préstimulation a été identifiée.
En conclusion, cette thèse souligne deux points majeurs pour caractériser l’étiologie et le développement de thérapies efficaces pour diminuer les déficits de mémoire de travail dans la schizophrénie. Premièrement, elle confirme la dysconnectivité transdiagnostique des réseaux neurocognitifs dans les troubles psychiatriques et souligne les altérations spécifiques des fonctions sensorimotrices dans la schizophrénie. Deuxièmement, elle démontre l'importance de déterminer des paramètres de stimulation fiables et individualisés pour optimiser l’efficacité de la SMT. / Schizophrenia is a severe mental illness characterized by substantial neurobiological alterations. A notable biomarker of this mental disorder is the functional brain dysconnectivity identified through functional magnetic resonance imaging. The functional brain connectivity alterations are mainly detected within the neurocognitive networks underlying higher brain functions. However, these dysfunctions are not unique to schizophrenia and are also found in other psychiatric disorders. The first objective of this doctoral thesis is to conduct a meta-analysis on resting-state functional brain dysconnectivity in schizophrenia and mood disorders to reveal commonalities and specificities of alterations, based on mean group effects. This innovative project based on the extraction of neuroanatomical labels includes 428 scientific articles. Meta-analytic results confirm transdiagnostic alterations in neurocognitive networks and highlight a specific dysconnectivity in sensorimotor networks in schizophrenia.
Among neurocognitive networks alterations, hyperconnectivity between the central executive network (CEN) and the default mode network (DMN) is associated with working memory deficits in schizophrenia, i.e. difficulties to temporarily hold and manipulate information in memory. Currently, there are no effective treatments for these deficits. Transcranial magnetic stimulation (TMS), already approved for depression, is a promising therapeutic approach. This neuromodulation tool operates by modulating dysfunctional connectivity networks. However, TMS effects to decrease working memory deficits in schizophrenia are mixed. A potential explanation lies in the standardized positioning of the stimulation target on the cortex, which does not account for significant inter-individual variability in the spatial organization of functional connectivity networks. Other methodological parameters, such as stimulation intensity, also impact the stimulation's effectiveness. The second project of this thesis aimed to conduct a retrospective study in healthy subjects to confirm the importance of specifically targeting the CEN to induce a functional modulation of these network. The impact of stimulation intensity was also evaluated. Results showed that a specific stimulation of CEN led to a decreased of the functional connectivity between the CEN and the DMN for subthreshold intensities.
Finally, a third project aimed to prospectively examine, in schizophrenia, the effects of a personalized TMS compared to a standard TMS on resting-state functional connectivity and working memory performance. Personalized TMS targets were defined based on patients’ individual connectivity patterns. The data analysis revealed a pronounced instability in connectivity networks, which did not allow us to conclude on the advantage of a personalized target to reduce hyperconnectivity between the CEN and the DMN and working memory deficits in schizophrenia. However, a relationship with pre-stimulation connectivity strength was identified.
In conclusion, this thesis highlights two major points for characterizing the etiology and the development of optimal TMS to reduce working memory deficits in schizophrenia. First, it confirms the transdiagnostic dysconnectivity of neurocognitive networks in psychiatric disorders and highlights specific alterations of sensorimotor functions in schizophrenia. Second, it demonstrates the importance of identifying reliable and individualized stimulation parameters to optimize the TMS.
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Características do envolvimento do Sistema Nervoso Central na Polirradiculoneuropatia Inflamatória Desmielinizante Crônica: um estudo mediante técnicas quantitativas de Imagem por Ressonância Magnética / Characteristics of involvement of the central nervous system in chronic inflammatory demyelinating polyneuropathy: a quantitative magnetic resonance imaging study.Carmo, Samuel Sullivan 27 June 2014 (has links)
A polineuropatia inflamatória desmielinizante crônica (PIDC) é uma síndrome caracterizada fundamentalmente pela disfunção do Sistema Nervoso Periférico e que afeta muito a qualidade de vida dos pacientes. O envolvimento da PIDC com o Sistema Nervoso Central tem sido descrito, maiormente como sendo subclínico, porém não há estudos sobre a caracterização deste envolvimento de uma forma ampla e quantitativa. Avaliamos 11 pacientes com PIDC, todos tratados e sem sinais clínicos de alterações centrais, e 11 controles, pareados em gênero e faixa etária de 19 a 69 anos. Foram adquiridas neuroimagens em uma máquina de Ressonância Magnética de alto campo (3T) usando diferentes técnicas de imagens; volumétricas ponderadas em T1, volumétricas de inversão e recuperação com atenuação de fluidos e ponderadas em T2, relaxométricas de cinco ecos para mapas de T2, de transferência de magnetização e por tensor de difusão. As imagens foram processadas em diferentes ferramentas computacionais e foram obtidos resultados para estudos da difusibilidade, volumetria, morfometria, tratometria e conectividade cerebral, além de achados radiológicos para os pacientes. As análises de grupos foram executadas por; 1) testes paramétricos monocaudais de duas amostras pareadas para os resultados da volumetria, da tratometria e conectividade cerebral; 2) mapeamento estatístico paramétrico para os resultados da morfometria baseada em voxel e; 3) estatística espacial baseada em tratos para os resultados da difusibilidade. Foram detectas alterações em todas as comparações. Os principais achados indicam um envolvimento possivelmente caracterizado por uma perda volumétrica encefálica generalizada, sobretudo nas regiões periventriculares associadas a ventrículos proeminentes acrescido de, um aumento da difusibilidade transversa e oblíqua nos maiores tratos de substância branca e, também há uma perda de densidade na substância branca periventricular e um aumento na substância cinzenta em uma região que sinaliza para o espessamento trigeminal bilateral e, uma redução geral da conectividade cerebral estrutural. / Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is a severe disease fundamentally characterized by dysfunction of the Peripheral Nervous System and affects greatly the quality of life of patients. The Central Nervous System (CNS) involvement in CIDP has not been described using recent quantitative neuroimaging techniques. We evaluated 11 patients with CIDP, all treated and without clinical signs of central alterations and 11 controls matched for gender and age group of 19 to 69 years. Magnetic Resonance Imaging were performed on a 3T scanner using different imaging techniques; structural 3D T1-weighted, fluid-attenuated inversion recovery, relaxometry with 5 echoes pulse sequence for T2 maps, magnetization transfer weighted and diffusion tensor imaging. The images were processed on different tools and were obtained results for the studies of diffusivity, volumetry, morphometry, tractometry, brain connectivity, and radiological findings of patients. Different statistical group analyses were performed in the quantitative results: 1) Parametric test for volumetry, tractometry and brain connectivity; 2) Parametric mapping for voxel morphometry; 3) Tract-based spatial statistics (TBSS) for diffusion coefficients. Changes were detected in all comparisons. In the patients, our main findings are: generalized loss brain volume more pronounced in periventricular regions associated with prominent ventricles, increased simultaneously perpendiculars and parallel diffusivity in the major tracts of the TBSS analyze, white matter density loss in the periventricular area, some bilateral trigeminal thickening, and general reduction of the brain connectivity. The CIDP affects the global brain and represents a demyelination in the CNS.
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Características do envolvimento do Sistema Nervoso Central na Polirradiculoneuropatia Inflamatória Desmielinizante Crônica: um estudo mediante técnicas quantitativas de Imagem por Ressonância Magnética / Characteristics of involvement of the central nervous system in chronic inflammatory demyelinating polyneuropathy: a quantitative magnetic resonance imaging study.Samuel Sullivan Carmo 27 June 2014 (has links)
A polineuropatia inflamatória desmielinizante crônica (PIDC) é uma síndrome caracterizada fundamentalmente pela disfunção do Sistema Nervoso Periférico e que afeta muito a qualidade de vida dos pacientes. O envolvimento da PIDC com o Sistema Nervoso Central tem sido descrito, maiormente como sendo subclínico, porém não há estudos sobre a caracterização deste envolvimento de uma forma ampla e quantitativa. Avaliamos 11 pacientes com PIDC, todos tratados e sem sinais clínicos de alterações centrais, e 11 controles, pareados em gênero e faixa etária de 19 a 69 anos. Foram adquiridas neuroimagens em uma máquina de Ressonância Magnética de alto campo (3T) usando diferentes técnicas de imagens; volumétricas ponderadas em T1, volumétricas de inversão e recuperação com atenuação de fluidos e ponderadas em T2, relaxométricas de cinco ecos para mapas de T2, de transferência de magnetização e por tensor de difusão. As imagens foram processadas em diferentes ferramentas computacionais e foram obtidos resultados para estudos da difusibilidade, volumetria, morfometria, tratometria e conectividade cerebral, além de achados radiológicos para os pacientes. As análises de grupos foram executadas por; 1) testes paramétricos monocaudais de duas amostras pareadas para os resultados da volumetria, da tratometria e conectividade cerebral; 2) mapeamento estatístico paramétrico para os resultados da morfometria baseada em voxel e; 3) estatística espacial baseada em tratos para os resultados da difusibilidade. Foram detectas alterações em todas as comparações. Os principais achados indicam um envolvimento possivelmente caracterizado por uma perda volumétrica encefálica generalizada, sobretudo nas regiões periventriculares associadas a ventrículos proeminentes acrescido de, um aumento da difusibilidade transversa e oblíqua nos maiores tratos de substância branca e, também há uma perda de densidade na substância branca periventricular e um aumento na substância cinzenta em uma região que sinaliza para o espessamento trigeminal bilateral e, uma redução geral da conectividade cerebral estrutural. / Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is a severe disease fundamentally characterized by dysfunction of the Peripheral Nervous System and affects greatly the quality of life of patients. The Central Nervous System (CNS) involvement in CIDP has not been described using recent quantitative neuroimaging techniques. We evaluated 11 patients with CIDP, all treated and without clinical signs of central alterations and 11 controls matched for gender and age group of 19 to 69 years. Magnetic Resonance Imaging were performed on a 3T scanner using different imaging techniques; structural 3D T1-weighted, fluid-attenuated inversion recovery, relaxometry with 5 echoes pulse sequence for T2 maps, magnetization transfer weighted and diffusion tensor imaging. The images were processed on different tools and were obtained results for the studies of diffusivity, volumetry, morphometry, tractometry, brain connectivity, and radiological findings of patients. Different statistical group analyses were performed in the quantitative results: 1) Parametric test for volumetry, tractometry and brain connectivity; 2) Parametric mapping for voxel morphometry; 3) Tract-based spatial statistics (TBSS) for diffusion coefficients. Changes were detected in all comparisons. In the patients, our main findings are: generalized loss brain volume more pronounced in periventricular regions associated with prominent ventricles, increased simultaneously perpendiculars and parallel diffusivity in the major tracts of the TBSS analyze, white matter density loss in the periventricular area, some bilateral trigeminal thickening, and general reduction of the brain connectivity. The CIDP affects the global brain and represents a demyelination in the CNS.
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