Thesis (Ph. D.)--University of California, San Diego, and San Diego State University, 2005. / Vita. Includes bibliographical references (leaves 149-164).

Thesis--University of Oklahoma. / Bibliography: leaves 44-47.

Given that neurocognitive impairment is a frequent complication of HIV-1 infection in Spanish-speaking adults, the limited number of studies assessing HIV-associated neurocognitive disorders (HAND) in this population raises serious clinical concern. In addition to being appropriately translated, instruments need to be modified, normed, and validated accordingly. The purpose of the current study was to examine the diagnostic utility of the HIV Dementia Scale (HDS) and International HIV Dementia Scale (IHDS) to screen for HAND in Spanish-speaking adults living with HIV infection. Participants were classified as either HAND (N = 47) or No-HAND (N = 53) after completing a comprehensive neuropsychological evaluation. Receiver operating characteristic analyses found the HDS (AUC =.706) was more sensitive to detecting HAND than the IHDS (AUC =.600). Optimal cutoff scores were 9.5 for the HDS (PPV = 65.2%, NPV = 71.4%) and 9.0 for the IHDS (PPV = 59.4%, NPV = 59.1%). Canonical Correlation Analysis found the HDS converged with attention and executive functioning. Findings suggest that while the IHDS may not be an appropriate screening instrument with this population, the HDS retains sufficient statistical validity and clinical utility to screen for HAND in Spanish-speaking adults as a time-efficient and cost-effective measure in clinical settings with limited resources.

La maladie de Huntington (MH) est une maladie neurodégénérative, autosomique, dominante. La MH se manifeste par des troubles moteurs, cognitifs, psychiatriques et/ou comportementaux. Les troubles cognitifs sont probablement parmi les mieux documentés dans la MH, perturbant la flexibilité, l’inhibition, la planification et la prise de décision. Des désordres des aptitudes en cognition sociale ont aussi été rapportés chez ces patients, dont en particulier des troubles de la reconnaissance des expressions faciales émotionnelles et de théorie de l’esprit (ToM).Les fonctions émotionnelles et leurs régulations sont actuellement peu caractérisées, tant chez les patients que chez les modèles animaux de la MH.Chez le modèle de rats transgéniques (tgHD rats), des perturbations des réponses émotionnelles et hédoniques ont été caractérisées à un âge précoce.L’objectif de cette thèse était de mieux caractériser les déficits émotionnels et leur impact sur les fonctions exécutives en étudiant (1) différentes tâches cognitives chez des patients MH et chez des modèles animaux de la MH (rats TgHD et rats BACHD) à différents stades de la maladie ; (2) en analysant l’impact d’états émotionnels induits (peur et plaisir) sur la prise de décision chez les patients MH (symptomatiques) et chez les rats BACHD à des âges différents. / Huntington's disease (HD) is an autosomal dominant genetic neurodegenerative disease. HD is characterized by a combination of motor, cognitive, psychiatric and behavioral symptoms. Social cognition skills disorders have also been reported in these patients, including in particular recognition disorders of emotional facial expressions and theory of mind (ToM).Emotional functions and regulations are currently poorly characterized in patients and in animal models of HD. In patients, loss of emotional control, and negative or positive emotions recognition deficits have been described.In the rat model of HD (tgHD rats), disturbances of emotional and hedonic responses were characterized at early stage.The aim of this thesis was to better define the emotional deficits and their impact on executive functions (1) different cognitive tasks among HD patients and in animal models of HD (TgHD and BACHD rats) at different stages of the disease; (2) by analyzing the impact of induced emotional states (fear and pleasure) on decision making in symptomatic HD patients and in BACHD rats at different ages.

Au décours d’un AVC, près de 50% des patients vont développer un trouble de la cognition dans les six premiers mois suivant l’accident. Ces déficits ont la particularité de pouvoir être de natures différentes, en touchant plusieurs domaines cognitifs distincts, parfois simultanément. A l’aide de batteries de tests neuropsychologiques dédiés, ces altérations cognitives ont pu être largement décrites et caractérisées. En revanche, les mécanismes sous-jacents l’apparition de ces troubles sont encore mal compris.Grâce aux possibilités d’analyse structurelle et fonctionnelle du cerveau, l’imagerie par résonance magnétique (IRM) est une technique de plus en plus utilisée pour identifier de nouveaux marqueurs diagnostiques des maladies neurodégénératives. L’objectif principal de de travail de thèse était de mieux comprendre les mécanismes physiopathologiques impliqués dans l’apparition de troubles cognitifs post-AVC à l’aide de méthodologies avancées en IRM.La première étude est une étude transversale comportant un versant pré-clinique chez des rats ischémiés et un versant clinique chez des patients victimes d’un AVC. Chez l’Homme, les résultats ont montré des anomalies morphologiques de l’hippocampe ainsi que des anomalies structurelles du cortex entorhinal chez les patients présentant un déficit cognitif 6 mois après AVC. Chez le rongeur, l’imagerie a montré des déformations des contours de l’hippocampe chez les rats ischémiés présentant des anomalies cognitives 6 mois après occlusion de l’artère cérébrale moyenne.Nous avons ensuite analysé les anomalies de connectivité fonctionnelle spécifiques aux troubles cognitifs survenant dans les 6 mois après un AVC chez l’Homme car certains travaux ont démontré l’importance des anomalies de communication fonctionnelle dans l’apparition des troubles cognitifs post-AVC. Nous avons ainsi identifié un réseau fonctionnel spécifique organisé autour du lobe frontal supérieur et temporal. De plus, chaque fonction cognitive était associée à un motif spécifique de connexions fonctionnelles altérées.Enfin, à l’aide d’algorithmes d’apprentissage machine, nous avons montré que ce réseau fonctionnel impliqué dans la génèse des troubles cognitifs post-AVC était un excellent marqueur prédictif des altérations cognitives chez l’Homme 3 ans après l’AVC.Ainsi, les mesures morphométriques du lobe temporal médian et de connectivité fonctionnelle globale apparaissent comme des marqueurs IRM complémentaires dans la caractérisation des troubles cognitifs post-AVC. L’ensemble de ces résultats suggèrent ainsi que des mécanismes physiopathologiques spécifiques seraient impliqués dans la survenue de des troubles cognitifs, permettant d’envisager dans l’avenir des prises en charge personnalisées pour les fonctions cognitives des patients victimes d’AVC. / After a stroke, nearly 50% of the patients are prompt to develop cognitive disorders in the first 6 months. These deficits can be various, affecting distinct cognitive functions and sometimes simultaneously. Using specific cognitive battery, these disorders can be well described and characterized. However, the mechanisms leading to the development of these cognitive impairments are poorly understood.In that sense, magnetic resonance imaging offers many possibilities for the detection of occurring cognitive disorders after a stroke. The aim of this study of to better define imaging markers that could help to better understand the physiopathology and potentially, using advances methods, predict the long-term outcome of stroke patients.First, a translational study highlighted morphological deformations of hippocampus and structural changes of entorhinal cortex in patients with a cognitive disorder 6 month after stroke compared to patients without. These alterations have also been found in a rat model of ischemia, that presented deformations of hippocampus 6 months after the ischemia compared to control animals.Second, many imaging studies reported that the post-stroke cognitive disorders could be more associated with spread dysfunctions rather than focal alteration at the lesion site. In that sense, we analyzed the functional alterations that could exist in patients with a cognitive disorder 6 months post-stroke compared to patients without. We then identified a functional network that seemed to be organized around regions in superior frontal and temporal lobes. Moreover, each cognitive function presented specific pattern of correlated connections in this network.Lastly, using machine learning algorithms, we showed that this identified functional network 6 months post-stroke can predict the diagnosis of cognitive impairment 30 months later, and also predict alterations of specific cognitive domains at the same time.Then, morphological measures of the medial temporal lobe and the global functional connectivity analyses appeared to be complementary MRI markers for the characterization of patients developing a cognitive disorder after stroke. All these results suggest then that specific physiopathological mechanisms could be involved in the appearance of post-stroke cognitive disorders, permitting to imagine potential new personalized care of post-stroke cognitive disorders.

A interface entre a linguagem e demais funções cognitivas tem sido objeto de estudo e a ampla e extensa distribuição dos circuitos neuronais torna o tema bastante complexo. A dificuldade em avaliar o desempenho cognitivo de afásicos faz com que estes pacientes sejam excluídos em estudos que buscam descrever alterações cognitivas após AVE. A avaliação de linguagem, isoladamente, não permite predizer o desempenho em outras habilidades cognitivas. Além disso, o processamento da linguagem se apóia nas habilidades de atenção, memória e funções executivas. A literatura nacional é escassa neste tema. Este trabalho teve como objetivos: avaliar o desempenho dos indivíduos afásicos em tarefas cognitivas não linguísticas (atenção, memória verbal e não verbal, funções executivas e habilidades visuoespaciais), comparar o desempenho dos afásicos e não afásicos nestas tarefas e relacionar o desempenho dos afásicos nas tarefas cognitivas não linguísticas com a gravidade da afasia. Participaram da pesquisa 47 indivíduos, maiores de 18 anos, de ambos os gêneros, com escolaridade mínima de dois anos, e diagnóstico de primeiro episódio de AVE, confirmado por TC de crânio. Aplicada a seguinte bateria de testes: Protocolo de Praxias Gestuais (TBDA), Fluência verbal semântica (animais) e Fonológica (FAS), Teste de Trilhas A e B, Teste de Cancelamento, Aprendizado de Palavras (CERAD), Aprendizado de Figuras (BBRC-Edu), Praxias construtivas (CERAD), Extensão de Dígitos (ED) e Desenho do Relógio (TDR). A amostra foi dividida em três grupos: afásicos (AF, n=21), não afásicos com lesão em hemisfério esquerdo (NAF E, n = 17) e não afásicos com lesão em hemisfério direito (NAF D, n = 9). O grupo de afásicos foi também subdividido em grupos grave (AFg) e leve (AFl). Não houve diferença estatisticamente significante entre os grupos nas provas de Cancelamento, Teste de Trilhas, Praxias Construtivas. Os afásicos apresentaram pior desempenho, em comparação aos grupos NAF E e NAF D, nas provas de fluência semântica, praxias gestuais, ED (ordens direta e inversa), Aprendizado de Palavras, Evocação das Praxias Construtivas (pontuação total), Aprendizado de Figuras e TDR. Na prova de extensão de dígitos, ordem direta, constatou-se pior desempenho do grupo AFg, em comparação ao AFl. Foi encontrada correlação entre a gravidade da afasia e o desempenho no teste de extensão de dígitos em ordem direta (rho=0,860, p=0,0001) e ordem inversa (rho=0,543, p=0,0152), e nas provas de praxias gestuais, especialmente nas praxias bucofaciais e respiratórias (rho=0,708, p=0,016). Constatou-se pior desempenho dos grupos AF e NAF E, em comparação ao grupo NAF D, nas provas de reconhecimento de palavras, Aprendizado de Figuras e TDR. Fatores como prejuízo na expressão oral e hemiparesia interferiram no desempenho dos sujeitos afásicos. A literatura aponta e o estudo confirma que os afásicos demonstram grande variabilidade no desempenho. Mostram-se necessários instrumentos mais adequados para a avaliação das habilidades não linguísticas em afásicos, além de estudos que possam ser replicados em diferentes populações. A avaliação do afásico que não considere somente as habilidades linguísticas, mas também outras funções cognitivas, pode auxiliar na elaboração de planejamentos terapêuticos mais adequados e, aumentar a eficácia da terapia de linguagem / The interface between language and other cognitive functions has been studied and the broad and extensive distribution of neural circuits has made the theme become very complex. The difficulty in assessing cognitive performance in aphasic patients excludes these patients from studies describing post-stroke cognitive deficits. Language assessment itself does not allow predicting the performance in other cognitive skills. Furthermore, language processing is supported by other cognitve abilities such as attention, memory, and executive functions. The literature about this theme in Brazil is scarce. This study aimed to evaluate the performance of aphasic patients in non-linguistic cognitive tasks (attention, verbal memory, non-verbal memory, executive functions and visuospatial skills), to compare the performance of aphasic and non-aphasic patients in non-linguistic cognitive tasks, and to correlate the performance of aphasic patients in nonlinguistic cognitive tasks and the aphasia severity. Forty seven individuals over 18 years old were enrolled in this research, both male and female, with minimum schooling level of two years, and diagnosis of first episode of stroke confirmed by CT brain scan. The following battery of tests was applied: Gesture Praxis Protocol (BDAE), Semantic (animals) and Phonemic (FAS) verbal fluency, Trail Making Test A and B, Cancellation Test, Word List Memory (CERAD), Figure Learning (BCB-Edu), Constructional Praxis (CERAD), Digit Span (DS) and Clock Drawing Test (CDT). The sample was divided in three groups: aphasic (AP,n=21), non-aphasic with left hemisphere lesion (NAP E, n = 17), and non-aphasic with right hemisphere lesion (NAP D, n = 9). The group of aphasic patients was also subdivided in severe (APs) and mild (APm). There was no significant statistical difference between the groups in the Cancellation Test, in the Trail Making test, and in the Constructional Praxis. The aphasic presented worse performance in comparison to groups NAP E and NAP D in Semantic fluency task, gesture praxis, DS (forward and backward), Word List Memory, Constructional Praxis recall (total score), Figure Learning, and CDT. In the Digit Span test, forward order, it was observed worse performance of group APs, in comparison to APm. It was verified a correlation between the aphasia severity and the performance in the DS test, forward order (rho=0,860, p=0,0001) and backward order (rho=0,543, p=0,0152), and in the Gesture Praxis test mainly in bucco-facial and respiratory praxis (rho=0,708, p=0,016). It was observed worse performance of groups AP and NAP E, in comparison to group NAP D, in the Word Recognition task, Figure Learning and CDT. The impairment of oral expression and hemiparesis interfered in the performance of aphasic patients. Literature points, and the study confirms, that aphasic patients show great variability in the performance. More adequate instruments for the assessment of non-linguistic skills in aphasic patients are necessary, besides studies that may be replicated in different populations. The assessment oof aphasic patients considering not only linguistic skills, but also other cognitive functions may help in the elaboration of more appropriate therapeutic planning and increase the efficacy of language therapy

No abstract available / ix, 115 leaves : ill. (some col.) ; 29 cm.

Thesis (Ph. D.)--St. Mary's University, San Antonio, Texas, 2007. / "December 2007." Includes bibliographical references (leaves 135-154) and appendices.

Diss. (sammanfattning) Umeå : Univ., 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.