Yes / Early diagnosis of Alzheimer’s disease (AD) is essential if treatments are to be administered at an earlier point in time before neurons degenerate to a stage beyond repair. In order for early detection to occur tools used to detect the disorder must be sensitive to the earliest of cognitive impairments. Virtual reality (VR) technology offers opportunities to provide products which attempt to mimic daily life situations, as much as is possible, within the computational environment. This may be useful for the detection of cognitive difficulties. We develop a virtual simulation designed to assess visuospatial memory in order to investigate cognitive function in a group of healthy elderly participants and those with a mild cognitive impairment. Participants were required to guide themselves along a virtual path to reach a virtual destination which they were required to remember. The preliminary results indicate that this virtual simulation has the potential to be used for detection of early AD since significant correlations of scores on the virtual environment with existing neuropsychological tests were found. Furthermore, the test discriminated between healthy elderly participants and those with a mild cognitive impairment (MCI).

Alzheimer's disease~(AD) is the most frequent neurodegenerative dementia and a growing health problem. Early and accurate diagnosis and prediction of AD is crucial because treatment may be most efficacious if introduced as early as possible. Neuropsychological testing, which is clinically used, sometimes fails to recognize probable dementia, especially to recognize the disease at an early time point such as the mild cognitive impairment~(MCI), which is the prodromal stage of AD. Recently, there has been a realization that magnetic resonance imaging~(MRI) may help diagnoses of AD and MCI. In this dissertation, we introduce an MRI-analysis based algorithm to help diagnose the illness before irreversible neuronal loss has set in, and to help detect brain changes between MCI patients who may convert and may not convert to AD. Given a set of brain MR images, the algorithm first calculates the distance between each pair of images via a registration process. Then images are projected from a high dimensional Euclidean space to a low dimensional Euclidean subspace based on the calculated distances, with a dimension reduction method. Finally classical supervised classification approaches are employed to assign images to appropriate groups in the low dimensional space. The classification accuracy rates we obtained in our experiments are higher than, or at least comparable to, those reported in recently published papers. Moreover, this algorithm can be extended to explore the pathology distribution of AD. Exploring the distribution of AD pathology is of great importance to reveal AD related regional atrophy at specific stages of the disease and provide insight into longitudinal sequence of disease progression. Calculating distances between different brain structures produces different classification accuracy. Those structures yielding higher classification accuracy are considered as pathological regions. Our experimental results on pathology localization are also compared with the reproduced results using other existing popular algorithms; the observations are consistent. / Ph. D.

Between 1.6 and 3.8 million sports-related concussions are sustained by persons living in the United States annually. While sports-related concussion was once considered to only result in immediate neurocognitive impairment and symptoms that are transient in nature, recent research has correlated long-term neurodegenerative effects with a history of sports-related concussion. Increased awareness and current media attention have contributed to concussions becoming a primary health concern. Although much research has been performed investigating the biomechanics of concussion, little is understood about the biomechanics that cause concussion in humans. The research presented in this dissertation investigates human tolerance to head acceleration using methods that pair biomechanical data collected from human volunteers with clinical data. Head impact exposure and injury risk are quantified and presented. In contrast to the publicly available data on the safety of automobiles, consumers have no analytical mechanism to evaluate the protective performance of football helmets. With this in mind, the Summation of Tests for the Analysis of Risk (STAR) evaluation system was developed to evaluate the impact performance of footballs helmets and provide consumers with information about helmet safety. The STAR evaluation system was designed using real world data that relate impact exposure to injury risk. / Ph. D.

Yes / National policies and evidence reviews recommend psychosocial interventions (PIs) as an essential support, particularly in the period following dementia diagnosis. However, the availability and uptake of these interventions is comparatively low. One of the reasons for this is that clinicians lack information about what might be provided and the potential benefits of different interventions. This paper identifies and describes psychosocial interventions for community dwelling people following diagnosis of mild to moderate dementia and presents the available evidence to inform practice decisions. A systematic scoping review was employed to map the evidence relating to PIs for this group. This identified 63 relevant studies, testing 69 interventions, which could be grouped into six categories; 20 cognition-oriented interventions; 11 behaviour-oriented; 11 stimulation-oriented; 13 emotion-oriented, 5 social-oriented and 9 multi-modal. There were three targets for outcome measurement of these PIs; the person with dementia, the family carer and the person-carer dyad. Over 154 outcome measures were identified in the studies with outcomes measured across 11 main domains. The lack of a classification framework for PIs means it is difficult to create a meaningful synthesis of the breadth of relevant evidence to guide clinical practice. Possible dimensions of a classification framework are proposed to begin to address this gap.

The concept of resilience, which indicates people's capability of using resources in difficult circumstances in order to reduce or prevent negative effects and achieve positive outcomes, has given a new perspective to the scientific literature on the experience of late-life memory loss and the experience of caring for persons with memory loss. The current research was guided by incorporation of resilience into the stress process model for assessing personal and caregiver burden associated with mild and more severe memory loss. I conducted two studies to investigate the association of protective factors with the well-being of people with dementia or mild cognitive impairment and their caregivers. The first study focused on the well-being of older persons with dementia (PwDs). I employed data from a large national sample of older adults to examine how the perceived social cohesion of neighborhoods affects quality of life among people with and without cognitive impairment in conjunction with their engagement in valued leisure activities. Findings revealed that, regardless of cognitive health status, all participants who perceived high neighborhood social cohesion reported better quality of life along with more participation in valued activities. However, PwDs reported significantly lower perceived neighborhood social cohesion, less involvement in valued activities, and poorer quality of life than persons without cognitive impairment. The second study focused on the well-being of caregivers for older persons with mild cognitive impairment (PwMCIs). I used dyadic data from families dealing with mild cognitive impairment to examine how well-being of caregivers for PwMCIs differed according to whether PwMCI-caregiver dyads had similar or different perceptions of the PwMCIs' cognitive impairment severity. Caregivers reported lower caregiving burden when they and PwMCIs had a similar cognitive impairment representation, or when caregivers rated the PwMCIs’ cognitive functioning more positively than the PwMCIs rated themselves. Also, PwMCIs’ and caregivers' perceptions, and their concordance or discrepancy in those perceptions, varied across the multiple domains related to MCI symptoms. These findings demonstrate that care dyads' perception of MCI-related deficits is not a unitary construct, and that the context of PwMCIs’ and caregivers’ dyadic illness appraisals is significantly associated with the caregivers' well-being. Taken together, the results of these two studies illustrate the value of considering resilience processes in people with cognitive impairment and their caregivers. Examining dimensions of resilience, in association with assessment of the intersecting effects of personal, interpersonal, and environmental factors, provides additional information about the effects of cognitive impairment on older adults’ well-being and the effects of assisting someone with cognitive impairment on caregiver well-being. / Ph. D.

Although not all persons with mild cognitive impairment (MCI) go on to develop Alzheimer's disease (AD), MCI is recognized as an early stage of AD. The effects of AD are devastating to all concerned. Research has identified that recognition of AD in its earliest stages and institution of known treatment modalities can forestall the ultimate outcome. Identification of the first subtle signs of MCI can assist in the recognition of this prodromal phase, and allow for institution of therapy while still in the initial stages. Unfortunately, the development of MCI is insidious in nature, thus making it difficult to detect. The purpose of this study was to identify areas of functional decline that occur in MCI in an effort to improve its early identification. A mixed-methods design that combined qualitative and quantitative methods was used. Fifty-three participants with memory complaints were interviewed using a semi structured interview technique with open-ended questions, the Montreal Cognitive Assessment (MoCA), the Geriatric Depression Scale (GDS) and a list of eighty-five items previously identified as indicative of functional decline. Twenty-nine persons were divided into two groups: 1) those identified as probable MCI (consensus diagnosis) (n=15) and possible MCI (based on screening examination) (n=14) and 2) those identified as Normal (no cognitive impairment) (n=10), and their subjective functional deficits compared. The findings suggest that there were certain areas of functional decline more commonly experienced by persons in the MCI group than by unimpaired. These include difficulty recalling details of information and forgetting conversations. There were also other changes identified, such as adaptations on the part of persons with MCI (an increased dependence on memory aids, for example, lists and calendars) and a dec rease in social activities leading to an increase in social isolation. Additionally identified were functional activities that appear to remain intact in persons with early MCI. This study highlights the subtlety with which MCI assaults the functional abilities of individuals, thus making its early identification problematic. The results of this study will contribute by providing information that will help professionals who are assessing persons experiencing memory issues for the possible presence of MCI. Additionally, it is hoped that these findings will assist in the development of a measurement tool designed to assess for possible MCI. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection

Made available in DSpace on 2016-04-29T13:18:08Z (GMT). No. of bitstreams: 1 Luciana Roberta Donola Cardoso.pdf: 1323389 bytes, checksum: 152237ce34951aabd58677f712755d06 (MD5) Previous issue date: 2008-05-14 / The Chronic Mild Stress (CMS) is an experimental animal model of depression induced by the exposure of rats to a set of moderate and uncontrollable aversive stimuli in a long and uninterrupted period of time. The purpose of this study was to investigate the relationship between performance in variable interval schedule of behavior and exposure to the protocol of stress (daily consumption of food and water, changes in body weight, frequency of answers issued in each bar and the frequency of reinforcements obtained when submitted to the same scheme competitor). The study design was composed of three experimental conditions: test consumption and preferably liquid; sessions operating on schedule competitor VI 10 (water) VI 10 (sucrose) and protocol of stress (CMS). Six male rats were used. One subject was used to control weight, not involved in any of the three experimental conditions. Five subjects were submitted to the protocol of stress and tests of consumption and preference of liquids throughout the experiment. Two subjects were submitted to the working sessions (VI competitor VI) before and after CMS and two subjects were submitted to the working sessions before, during and after the CMS. The results were: 1) all subjects showed loss of body weight during the exposure to stressors. 2) The four subjects submitted to the working sessions showed recovery of body weight after the suspension of the protocol. 3) All subjects showed an increase in daily consumption of water and feed during the CMS, despite the loss of weight in this period. 4) Liquid consumption and the percentage of sucrose intake was higher during the CMS for the four subjects submitted to the working sessions, featuring a reduction in the last week of exposure to the protocol of stress. 5) All subjects expressed a greater number of responses in the bar corresponding to sucrose before exposure to CMS. Meanwhile, during and after CMS, a preference for water became outstanding. 6) The subjects received almost all of the planned reinforcements of both magnitudes (sucrose solution or pure water) in the three periods of assessment. We conclude that: 1) the loss of weight during the CMS seems to be related to the combination of aversive stimuli compound by the Protocol of stress and deprivation of water and food intermittent making up this protocol 2) the increase in the total consumption of liquids during the CMS appear to be related to the submission to the working sessions in variable interval before submission to the Protocol 3) the exposure of the subject to a scheme of variable interval, before CMS, slows the decline in the consumption of liquid and increases consumption of fluids during the CMS / O Chronic Mild Stress (CMS) é um modelo animal experimental de depressão induzida por meio da exposição de ratos a um conjunto de estímulos aversivos moderados e incontroláveis, apresentados por um longo e ininterrupto período de tempo. O objetivo deste estudo foi investigar a possível relação entre o desempenho em esquema de intervalo variável e a exposição ao protocolo de estresse, quanto ao consumo diário de ração e água e as subseqüentes alterações no peso corporal; no consumo e na preferência de líquidos; na freqüência de respostas emitidas em cada barra e na freqüência de reforços obtidos nas mesmas quando submetidos ao esquema concorrente. O delineamento foi composto por três condições experimentais: teste de consumo e de preferência de líquidos; sessões operantes em esquema concorrente VI 10 (água) VI 10 (sacarose) e protocolo de estresse (CMS). Foram utilizados seis ratos machos, sendo que um sujeito foi utilizado para controle de peso, não submetido a nenhuma das três condições experimentais. Cinco sujeitos foram submetidos ao protocolo de estresse e aos testes de consumo e preferência de líquidos durante todo o experimento. Dois sujeitos foram submetidos às sessões operantes (concorrente VI VI) antes e depois do CMS e dois sujeitos foram submetidos às sessões operantes, antes, durante e depois do CMS. Os resultados obtidos foram: 1) todos os sujeitos apresentaram perda de peso corporal durante a exposição aos estressores. 2) Os quatro sujeitos submetidos às sessões operantes apresentaram recuperação do peso corporal após a suspensão do protocolo; 3) todos os sujeitos apresentaram aumento no consumo diário de água e ração durante o CMS, apesar da perda de peso neste período; 4) consumo total de líquidos e a porcentagem de sacarose ingerida foi maior durante o CMS para os quatro sujeitos submetidos as sessões operantes, apresentando uma redução na última semana de exposição ao protocolo de estresse; 5) todos os sujeitos emitiram um maior número de respostas na barra correspondente a sacarose antes da exposição ao CMS. Entretanto, durante e depois do CMS a preferência por água se tornou sobressalente; 6) os sujeitos obtiveram a quase totalidade de reforços programados de ambas as magnitudes (solução de sacarose ou água pura ) nos três períodos de avaliação. Conclui-se que: 1) a perda de peso corporal durante o CMS parece estar relacionada à combinação dos estímulos aversivos compostos pelo protocolo de estresse e à privação de água e ração intermitente que compõem este protocolo 2) o aumento no consumo total de líquidos durante o CMS parecem estar relacionados à submissão às sessões operantes em intervalo variável antes da submissão ao protocolo 3) a exposição dos sujeitos a um esquema de intervalo variável, antes do CMS, não só teria um efeito de retardar a diminuição no consumo de líquidos, como aumentar o consumo de líquidos durante o CMS

Frontal lobe atrophy (FLA) is associated with late-life depression and cognitive impairment, although the pathogenesis of FLA in stroke is unclear. In an aim to ascertain whether FLA is affected by WMLs, we analyzed the MRIs of 471 Chinese ischemic stroke patients. Lobar atrophy was defined by a widely-used visual rating scale. WML severity was rated using the Fazekas scale. There was no correlation between PVH and DWMH and temporal and parietal atrophy. The results of this study suggest that FLA in ischemic stroke may be associated with SVD. / Poststroke depression (PSD) is the most common form of poststroke psychiatric morbidity. Small subcortical infarcts (SSIs) can result from small vessel disease (SVD) and large artery disease (LAD). No study has yet explored PSD in different etiological types of SSIs. To address this gap, 127 patients with SSIs resulting from LAD or SVD were examined. PSD was evaluated with the Geriatric Depression Scale (GDS) three months after stroke. The LAD group had a significantly higher frequency of PSD, and LAD was found to be a significant independent risk factor for PSD. This study suggests that cerebral blood perfusion may play an important role in PSD. / Post-stroke emotional lability (PSEL) is a distressing and embarrassing complaint among stroke survivors. Lesions located in various cortical and subcortical areas are thought to be involved in the pathophysiology of PSEL.The clinical significance of microbleeds (MBs) in the development of psychiatric conditions following stroke is unknown. We carried out a study to examine the association between PSEL and MBs in 519 Chinese patients with acute ischemic stroke admitted consecutively. PSEL was evaluated three months after the index stroke, and the number and location of MBs were evaluated with MRI. According to Kim's criteria, 74 (14.3%) of the patients had PSEL. Our results suggest that MBs in the thalamus may play a role in the development of PSEL. The importance of MBs in PSEL and other psychiatric conditions in stroke survivors warrants further investigation. / The first study reported in this thesis involved 328 Chinese ischemic stroke patients who were administered a series of neuropsychological tests covering seven domains three months after stroke. Two hundred and fifty-six of these patients were followed-up for one year. Volumetry of the infarcts, WMLs, and hippocampus atrophy on magnetic resonance imaging (MRI) was conducted. The prevalence of cognitive impairment was 54.9% at baseline and 52.4% at the one-year follow-up, although most of the patients (85.5%) remained cognitively stable. The evolution of cognitive impairment no dementia (CIND) at the one-year follow-up was bidirectional, with 11.2% progressing to dementia and 21.0% reverting to cognitive intact. WMLs volume rather than hippocampal volume was a significant predictor of cognitive impairment, cognitive decline, and delayed dementia. WMLs also had an independent effect on executive function, attention, visual memory, visuoconstruction, and visuomotor speed. / This thesis investigates the clinical and imaging characterization of cognitive impairment and psychiatric morbidity in Chinese stroke patients. The conclusions of the studies reported herein can be summarized as follows. (1) The prevalence of cognitive impairment is high among Chinese poststroke patients, but most remain cognitively stable at one year after stroke; WMLs rather than hippocampal atrophy predict cognitive impairment, longitudinal cognitive decline, and delayed dementia; (2) DLPFC atrophy is correlated with poor verbal fluency in elderly women with stroke, but not in their male counterparts; (3) LAD may be associated with PSD in patients with small subcortical infarcts; (4) MBs in the thalamus are associated with PSEL; (5) frontal lobe infarction and diabetes may be risk factors of insomnia symptoms in stroke patients; and (6) FLA in ischemic stroke may be associated with SVD. (Abstract shortened by UMI.) / Chen, Yangkun. / Adviser: Wai Kwong Tang. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 217-238). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Since neuroinflammation is present in patients with mild cognitive impairment (MCI) andAlzheimer's disease (AD) and since cholinesterase inhibitors increases the level ofacetylcholine, the aim was to investigate whether inflammatory markers of cholinoceptive cellsare affected in these patients. Near a biological hallmark of AD, amyloid plaque, activatedastrocytes and microglia can be found and higher levels of proinflammatory cytokines, i.e. IL-1β. To study the inflammatory response, proteins GFAP and S100B are used as CSF glialmarkers. IL-1β can bind to the membrane-bound IL-1 receptor or soluble sIL-1β-RII. When IL-1β binds to the soluble receptor instead of the membrane-bound receptor, no intracellular signalpropagation occur, thereby sIL-1βRII exerts an antagonistic effect and diminishedinflammatory responses. Thus a reduction in ratio of IL-1β to sIL-1RII levels may be indicativeof anti-inflammatory response. Available data on CSF GFAP, S100B, IL-1β and sIL-1β-RIIlevels in AD patients and MCI patients was used. MCI group were longitudinally followedafter start of treatment with a cholinesterase inhibitor (ChEI). AD group had data from baselineand after short-term treatment with a ChEI. The statistics application StatView was used toanalyse data. The activity of the cholinesterase enzymes, BuChE and AChE showed significantinhibition in the CSF of the MCI patients compared to baseline CSF GFAP level wassignificantly lower in MCI than AD patients at baseline. The levels of both GFAP and S100Bwere increased with time in MCI patients to comparable levels in the AD patients, indicative ofastroglial activation in MCI patients. However, the ratio of IL-1β to sIL-1RII showed alongitudinal reduction in the MCI patients after the treatment with the ChEIso that this ratiowas significantly higher in AD than in MCI patients. Thus despite the activation of astroglialcells in the treated MCI patients the proinflammatory effect of IL-1β was prevented byinduction of sIL-1βRII levels indicative of an anti-inflammatory outcome of treatment. Thisstudy suggests that proper activation of astroglial cells may have beneficial effect on ADpathogenesis, and conversion of MCI to AD. It also suggests that cholinesterase inhibitors may have an anti-inflammatory effect.

Ce travail de thèse s’articule autour de trois études complémentaires. La première aborde la validation française d’un test rapide d’évaluation des fonctions supérieures: le Barrow Neurological Institute Screen for higher cerebral functions (B.N.I.S). Cette étude a permis de rendre disponible en langue française un outil rapide qui évalue les fonctions cognitives classiques mais aussi les capacités émotionnelles et sociocognitives, fonctions généralement non intégrées dans ce type de test. La seconde étude, menée auprès de participants présentant un Mild Cognitive Impairment (M.C.I), a ensuite permis de mettre en évidence la nécessité de prendre en compte l’évaluation émotionnelle. Les participants M.C.I présentent un profil spécifique au B.N.I.S., notamment aux subtests d’affectivité, d’orientation, de mémoire et d’auto-évaluation de la performance mnésique. Enfin, la troisième étude analyse les performances de reconnaissance faciale des émotions et de raisonnement social au cours du vieillissement normal, le Mild Cognitive Impairment et la démence de type Alzheimer (DTA) au stade débutant. Nous observons un déclin des capacités de reconnaissance faciale des émotions et de raisonnement social au cours du vieillissement normal qui s’accentue significativement au cours de la DTA. Un profil spécifique est retrouvé pour le M.C.I avec un déclin en raisonnement social mais des capacités de reconnaissance faciale émotionnelle comparables aux sujets âgés du groupe contrôle. L’évaluation des capacités émotionnelles devrait être davantage intégrée aux bilans neuropsychologiques afin de mieux orienter les modalités de prise en charge de la population vieillissante. / This research presents three complementary studies: (1) the french validation of the Barrow Neurological Institute Screen for higher cerebral functions (B.N.I.S), developed by G. Prigatano in 1991. We have assessed 167 subjects from 15 to 84 years within a french population. The goal is :1) to promote a new short screening instrument dedicated to cognitive and emotional functions, usually emotional functions are not integrated in neuropsychological assessments ; (2) to apply the B.N.I.S to Mild Cognitive Impairment (M.C.I) subjects (N=39) in order to highlighted the importance of the emotional assessment in this type of population and found a specific profile at the substests named: affectivity, orientation, memory and self-assessment of the mnesic performance ; (3) to analyze, with more precision, the performance of emotional facial recognition and social reasoning during normal ageing (N=54), M.C.I (N=25) and Alzheimer disease (AD) at the early stage (N=17). A decline of sociocognitive capacities is observed during the ageing and seems to become more important during the course of M.C.I and the AD. A specific profile was found for each group. The assessment of emotional capacities seems relevant and should be more integrated into the neuropsychological assessments, in order to improve diagnosis and to propose the best modalities of care for the ageing population.