Wong, Adrian. / "August 2007." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 183-221). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.

The purpose of this investigation was to examine the validity of the Woodcock Johnson Tests of Cognitive Ability-Revised (WJTCA-R) in discriminating between individuals with neurological or psychiatric impairments and those without known impairment. The primary question was whether WJTCA-R Standard Battery test scores significantly differentiated between individuals with brain-damage (n = 36), depression (n = 21), and without known impairments (n = 32). Archival data obtained for the development of a new neuropsychological assessment measure utilizing the WJTCA-R was analyzed. The results of a discriminant functions analysis indicated that significant differences between the groups existed on the WJTCA-R. Based on WJTCA-R Standard Battery performance alone, participants had a 53% chance of being correctly classified into their diagnostic group. Brain-damaged individuals had the best chance of being correctly classified while correct classification of depressed individuals was only slightly greater than that obtained from random assignment. In addition to moderately supporting the use of a multi-factored, theory-driven assessment instrument, the results of this study have clinical relevance for the development of diagnosis-specific recommendations for brain-damaged and depressed individuals. / Department of Educational Psychology

[Truncated abstract] Background: Dementia, largely due to Alzheimer's disease (AD), is a major public health problem. The early identification of disease is an important challenge for clinicians because treatment of AD is now available. A simple and accurate means of stratifying risk for AD and identifying early disease is needed so that risk factor modification and treatment can occur optimally. To date, despite many attempts, an accurate means of standardising an approach to the assessment of subtle cognitive symptoms has not been developed. A subjective complaint of poor memory has been identified as a possible marker for underlying brain disease. This study examines the utility of neuropsychological scores, homocysteine levels, APOE genotyping and brain imaging as predictors of cognitive decline in individuals with subjective memory complaint (SMC). Method Eighty subjects with SMC were recruited from memory clinics and the community (MC: 1). Forty-two control subjects were also examined (MC: 0). CAMDEX was used to describe baseline clinical features. The CAMCOG was used as a global test of cognition and was administered annually for four years. At baseline, neuropsychological testing was administered. Cranial CT scanning, measurement of plasma homocysteine and APOE genotyping were completed. Categorical variables were analysed using chi-square according to Pearson's method. Continuous data was analysed using Student's t-tests and Mann-Whitney tests. A logistic regression model was used to identify independent contributors to the presence of memory complaint. Participants were then matched for age, gender and time to follow-up (up for three years) to determine longitudinal predictors of cognitive decline. ... Baseline CAMCOG scores were greater in the control group (MC:0 = 98.3 ? 2.8, MC:1 94.2 ? 5.5, Z ?4.46, p 0.000). There were no differences in neuropsychological scores, concentration of total plasma homocysteine, APOE genotype or brain scan measurements. Using the Wald stepwise selection method, logistic regression could not be established due to non-convergence regardless of whether or not the continuous variables were re-coded into dichotomous variables. A matching process that created 32 pairs of controls/subjects allowed follow-up analysis. The controls showed significant improvement with time on the CAMCOG unlike subjects (mean ? SD, controls 1.5 ?-3.0, Z - 2.61, p 0.01, subjects 0.2 ? 3.2, Z ? 0.24, p 0.81). The logistic regression analysis showed that group membership could not be defined by any single independent variable. When group membership was abandoned and those with stable scores were compared to those who declined no clear meaningful independent predictors of decline apart from age were identified. Conclusions: Methodological issues such as small sample size and inadequate follow up duration were identified that may have precluded identification of predictive factors for cognitive decline. The results indicate that complaints of memory problems are not associated with established risk factors for Alzheimer's disease and fail to predict objective cognitive decline over three years. Future studies should continue trying to identify robust predictors of cognitive decline in later life.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

While most people with schizophrenia face the functional consequences of a lifelong disorder, very few studies have investigated the specific domain of daily living activities performance. The purpose of this thesis was to examine the relationships between daily activity performance, cognitive deficits, and community functioning in people with schizophrenia. More specifically, the objectives were: 1) to describe functional limitations during daily task performance, 2) to explore the existence of subgroups of participants with similar functional limitations profiles, 3) to explore the relationships between daily task performance and cognitive functions as well as 4) with community functioning. This thesis tested the hypothesis that limitations in task performance negatively influence community functioning. / A sample of 82 individuals with schizophrenia and 28 healthy controls participated in this study and were assessed during a meal preparation task with the Perceive, Recall, Plan and Perform (PRPP) System of Task Analysis and on cognitive tests of visuospatial memory, spatial working memory, visuomotor coordination, planning and selective attention. Community functioning was assessed with the Independent living Skills Survey and the Multnomah Community Ability Scale. Limitations in the Perceive, Recall and Plan quadrants of the PRPP System, were found in participants with schizophrenia when compared to a control group (n = 28), as well as in the complete sample (n = 82). Participants in the high-efficiency subgroup ( n =36) were more independent in daily living and performed better on the visuospatial associative learning task than the low-efficiency subgroup (n = 46). At the specific level of individual profiles, participants were distributed along a continuum of low- to high-functioning on the PRPP System factors and on functional, cognitive, and clinical characteristics. / The associative learning task was most associated with task performance, along with working memory and planning. Finally, less efficient planning skills were associated with a lower level of community functioning, confirming the hypothesis. These results emphasize the relationship of associative visual memory to daily task performance, as well as that of efficiency in daily activities for residential status. Integrating these findings into the rehabilitation process will contribute to better meeting the needs of people with schizophrenia.

Doctor of Philosophy(PhD) / In recent years there has been a substantial increase in research examining the role of subjective memory complaints (SMC) in cognitive function and Alzheimer’s disease. These studies have related SMC to many different cognitive outcomes, such as retaining normal cognitive function, a fluctuating cognitive performance and the development of Alzheimer’s disease. Most of these studies have focused on older populations and have employed a limited assessment of cognitive function. This limits the available evidence regarding the clinical utility of SMC. The literature on the role of SMC in younger subjects is scarce. It is not known whether memory complaints are useful in predicting future cases of Alzheimer’s disease in younger community-based subjects. Aims: The main aim of the present study was to determine whether SMC predict the development of cognitive impairment in a younger cohort of subjects, many of whom were under the age of 70 years (73%), based on their risk profile and neuropsychological assessment. A further aim was to ascertain whether the DRS or 7MS are sensitive screening tools for MCI and examine whether the presence of SMC affects the 3-year cognitive outcome of subjects. To address these aims, this study consisted of two parts: a cross-sectional design and a longitudinal follow-up component. Methods: This study was carried out with 86 community-dwelling subjects recruited via advertisement within the catchment area of Central Sydney Area Health Service. The mean age of the subjects was 63.1 years (SD=8.4). Subjective memory complaints were assessed using a single question. Cognitive function was assessed using a comprehensive battery of tests, selected on the basis of their sensitivity to identifying cognitive impairment typically associated with Alzheimer’s disease. After the initial analysis between those with SMC and without SMC, subjects were further classified according to their performance on an episodic memory task (i.e., delayed verbal recall, Rey, 1964) as having normal memory function, SMC or aMCI. Results: Part 1 - Subjective memory complaints (SMC) were reported by 63% of the sample. The initial analysis between subjects with SMC (n=54) and without SMC (n=32) suggested an initial relationship between SMC and cognitive functioning. Subjects with SMC had impaired global cognitive functioning on two brief screening tests (7MS and DRS), working memory, verbal recall and visuomotor speed. However, subsequent screening with the delayed verbal recall test showed that 12 of the 54 subjects with SMC demonstrated significant cognitive impairment, scoring 2 SD below the control group mean. After these subjects were removed to form the aMCI group, the cognitive differences between subjects with SMC and without SMC were no longer apparent. Subjects with aMCI showed evidence of multiple cognitive deficits (below 1 SD of control group mean) with a high percentage of subjects demonstrating impairment on tests of verbal learning, verbal recall, verbal ability and visuomotor speed. Further analysis showed a significant association between age and subjects identified as having SMC (r=-.581, p<.001) and aMCI (r=.692, p<.001). From the age of 60 onwards, both the SMC and aMCI groups demonstrated a more rapid cognitive decline with increasing age in several cognitive domains. Part 2 - After a mean interval of 3.2 years, 43 subjects were followed up. Subjects with aMCI showed evidence of greater decline on both screening tests (7MS; DRS), whilst the SMC group had significantly higher scores. This trend was also apparent with other neuropsychological testing. The analysis of change over time in cognitive function showed that the majority of subjects (both SMC aMCI) either remained stable or improved their cognitive performance. It is likely that the small sample size and short follow-up interval of the present study contributed to the present observation of no change in cognitive function over time. Discussion: The present findings suggest that subjective memory complaints are a poor predictor of cognitive function. In isolation, SMC are unlikely to be useful for identifying cases with significant cognitive impairment. This is particularly relevant for subjects under the age of 70 years. However, for subjects over the age of 70 years, SMC are likely to identify significant cases with neuropsychological assessment (such as animal fluency and delayed recall). Conclusion: The present study showed that SMC are a poor predictor of cognitive function in subjects under the age of 70 years. This study provided evidence that selected and relatively quick to administer formal neuropsychological tests of cognitive function (in particular tests of animal fluency and delayed recall) are better able to identify those at risk of developing cognitive impairment associated with Alzheimer’s disease, at an earlier age. This would thus allow exposure to earlier treatment options, such as donepezil, aricept, vitamin E, and memantine”.

Doctor of Philosophy(PhD) / In recent years there has been a substantial increase in research examining the role of subjective memory complaints (SMC) in cognitive function and Alzheimer’s disease. These studies have related SMC to many different cognitive outcomes, such as retaining normal cognitive function, a fluctuating cognitive performance and the development of Alzheimer’s disease. Most of these studies have focused on older populations and have employed a limited assessment of cognitive function. This limits the available evidence regarding the clinical utility of SMC. The literature on the role of SMC in younger subjects is scarce. It is not known whether memory complaints are useful in predicting future cases of Alzheimer’s disease in younger community-based subjects. Aims: The main aim of the present study was to determine whether SMC predict the development of cognitive impairment in a younger cohort of subjects, many of whom were under the age of 70 years (73%), based on their risk profile and neuropsychological assessment. A further aim was to ascertain whether the DRS or 7MS are sensitive screening tools for MCI and examine whether the presence of SMC affects the 3-year cognitive outcome of subjects. To address these aims, this study consisted of two parts: a cross-sectional design and a longitudinal follow-up component. Methods: This study was carried out with 86 community-dwelling subjects recruited via advertisement within the catchment area of Central Sydney Area Health Service. The mean age of the subjects was 63.1 years (SD=8.4). Subjective memory complaints were assessed using a single question. Cognitive function was assessed using a comprehensive battery of tests, selected on the basis of their sensitivity to identifying cognitive impairment typically associated with Alzheimer’s disease. After the initial analysis between those with SMC and without SMC, subjects were further classified according to their performance on an episodic memory task (i.e., delayed verbal recall, Rey, 1964) as having normal memory function, SMC or aMCI. Results: Part 1 - Subjective memory complaints (SMC) were reported by 63% of the sample. The initial analysis between subjects with SMC (n=54) and without SMC (n=32) suggested an initial relationship between SMC and cognitive functioning. Subjects with SMC had impaired global cognitive functioning on two brief screening tests (7MS and DRS), working memory, verbal recall and visuomotor speed. However, subsequent screening with the delayed verbal recall test showed that 12 of the 54 subjects with SMC demonstrated significant cognitive impairment, scoring 2 SD below the control group mean. After these subjects were removed to form the aMCI group, the cognitive differences between subjects with SMC and without SMC were no longer apparent. Subjects with aMCI showed evidence of multiple cognitive deficits (below 1 SD of control group mean) with a high percentage of subjects demonstrating impairment on tests of verbal learning, verbal recall, verbal ability and visuomotor speed. Further analysis showed a significant association between age and subjects identified as having SMC (r=-.581, p<.001) and aMCI (r=.692, p<.001). From the age of 60 onwards, both the SMC and aMCI groups demonstrated a more rapid cognitive decline with increasing age in several cognitive domains. Part 2 - After a mean interval of 3.2 years, 43 subjects were followed up. Subjects with aMCI showed evidence of greater decline on both screening tests (7MS; DRS), whilst the SMC group had significantly higher scores. This trend was also apparent with other neuropsychological testing. The analysis of change over time in cognitive function showed that the majority of subjects (both SMC aMCI) either remained stable or improved their cognitive performance. It is likely that the small sample size and short follow-up interval of the present study contributed to the present observation of no change in cognitive function over time. Discussion: The present findings suggest that subjective memory complaints are a poor predictor of cognitive function. In isolation, SMC are unlikely to be useful for identifying cases with significant cognitive impairment. This is particularly relevant for subjects under the age of 70 years. However, for subjects over the age of 70 years, SMC are likely to identify significant cases with neuropsychological assessment (such as animal fluency and delayed recall). Conclusion: The present study showed that SMC are a poor predictor of cognitive function in subjects under the age of 70 years. This study provided evidence that selected and relatively quick to administer formal neuropsychological tests of cognitive function (in particular tests of animal fluency and delayed recall) are better able to identify those at risk of developing cognitive impairment associated with Alzheimer’s disease, at an earlier age. This would thus allow exposure to earlier treatment options, such as donepezil, aricept, vitamin E, and memantine”.

No description available.

Diabetes is a disease with a deleterious pathology that currently impacts 4.5 million individuals within the United States. This study examined the ability of a specific neuropsychological battery to identify and classify dementia type, investigated the impact of diabetes on cognition and analyzed the ability of the memory measures of the 7 Minute Screen (7MS) and the Rey-Osterrieth Recall to correctly categorize dementia type when not used in combination with a full battery. The battery in addition to exhaustive patient history, medical chart review and pertinent tests were used in initial diagnosis. Results indicated the battery was sufficient in the identification and classification of dementia type. Within the sample, diabetes did not appear to significantly impact overall battery results whereby only two measures were minimally affected by diabetes. Finally, the memory measures of the 7MS and the Rey-Osterrieth Recall were sufficient to predict membership into the Alzheimer's (AD) and vascular dementia (VD) groups with 86.4% accuracy. The classification percentage dropped to 68.3% with addition of the mild cognitive impairment category. The full battery correctly classified AD and VD dementia 87.5% and appeared to be the most robust.

Sintomas psicológicos e comportamentais da demência (SPCD) são comuns e associados com pior prognóstico, altos custos no cuidado, aumento de estresse do cuidador e institucionalização precoce. O objetivo do presente estudo é avaliar a prevalência de SPCD em uma amostra populacional com 60 anos ou mais da cidade de São Paulo, com diagnóstico de Demência de Alzheimer (DA) e comprometimento cognitivo sem demência (CIND), bem como correlacioná-la com a gravidade dos déficits cognitivos e com estresse do cuidador. De 1560 indivíduos entrevistados, 42 receberam o diagnóstico de DA e 16 de CIND. Um total de 70,5% de indivíduos com DA apresentou um ou mais SPCD. Apatia (56,09% dos indivíduos), depressão (48,78%), alteração do sono (34,14%), e ansiedade (29,26%) foram os sintomas mais prevalentes em DA. Estas alterações foram significativamente mais prevalentes no grupo com DA do que no grupo de controles sadios e com CIND. Embora o grupo com CIND tenha apresentado mais sintomas do que o grupo de controles normais, não houve diferença significativa entre ambos. Alucinação, agitação/agressão, depressão, apatia, comportamento motor aberrante e alterações do sono foram significativamente mais prevalentes nos estágios mais avançados da doença. Os sintomas que mais se correlacionaram com estresse do cuidador foram delírios, agitação/agressão, comportamento motor aberrante e desinibição / Behavioral and psychological symptoms of dementia (BPSD) are common and associated with worse prognosis, higher costs of care, increased caregiver burden and earlier nursing home entry. The purpose of this study is to determine BPSD prevalence in Alzheimer Disease (AD) and cognitively impaired not dement (CIND) diagnosis in a community sample with 60 years or over of São Paulo city, and correlate these with intensity of cognitive deficit and caregiver burden. Of the 1560 individual interviewed, 42 had AD and 16 had CIND. An overall of 70,5% of individuals with AD reported one or more BPSD. Apathy (56,09% of individuals), depression (48,78%), sleep alterations (34,14%), and anxiety (29,26%) were the most prevalent disturbances in AD. These disturbances were significantly more prevalent in participants with AD than in those normal and with CIND. Although the CIND group had more symptoms than normal control group, this difference was not significant. Hallucination, agitation/aggression, depression, apathy, aberrant motor behavior and sleep alterations were significantly more common in participants with advanced dementia. The symptoms that highly correlate with caregiver burden were delusion, agitation/aggression, aberrant motor behavior and disinhibition