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Biomedical subjects

Linda C W Lam

Publications and source records attributed to Linda C W Lam.

14 recordsLinked to original sources
PubMed2007

Depression and apathy affect functioning in community active subjects with questionable dementia and mild Alzheimer's disease.

BACKGROUND: The relationships between apathy, depression and functional impairment in questionable dementia (QD) and Alzheimer's disease (AD) are complex. This study aimed to explore the interactions between severity of apathy, depression and functional performance; and to investigate the effects of apathy alone, depression alone and coexistence of apathy and depression on the functional performance in subjects with QD and AD. METHODS: One hundred ninety-five subjects with QD and 96 subjects with mild AD were recruited. Apathy and depression were rated using the Neuropsychiatric Inventory and functional disability was measured using the Disability Assessment for Dementia (DAD). RESULTS: Severity of apathy and depression symptoms were associated with poorer functional performance in QD and apathy was associated with poorer functional performance in AD. In QD, subjects with apathy, depression, or coexistence of apathy and depression had poorer functional performance than those with neither apathy nor depression. The coexistence of apathy and depression did not produce more severe functional disability than apathy alone or depression alone. In AD, subjects with apathy had poorer functional performance than those without apathy. Depression in the absence of apathy was not associated with more severe functional disability. CONCLUSION: Apathy and depression symptoms are common in the early course of AD. Apathy and depression had different effects on functional performances in the subjects with QD from those with AD.

Activities of Daily Living↗
PubMed2006

Apolipoprotein E epsilon4 allele is associated with vascular dementia.

BACKGROUND/AIMS: The apolipoprotein E (ApoE) exon 4 polymorphism has been associated with vascular dementia (VaD) risk. Since not all studies confirm this finding, we explored this association in a case-control study. METHODS: We genotyped ApoE in 144 VaD patients and 251 controls. RESULTS: VaD patients were more likely than controls to have ApoE epsilon3/epsilon4 or epsilon4/epsilon4 genotypes: 23.6% versus 15.1%, odds ratio (OR) = 1.7, p = 0.036. This association remained significant after adjustment for age, sex, hypertension and diabetes by multiple logistic regression: OR = 1.9, p = 0.030. The association of epsilon3/epsilon4 or epsilon4/epsilon4 genotypes with VaD was strong among people with hypertension (OR = 2.9, p = 0.007) or diabetes (OR = 6.5, p = 0.011). The association was absent among people without hypertension (OR = 1.1, p = 0.79) or diabetes (OR = 1.3, p = 0.43). CONCLUSION: This interaction with hypertension and diabetes should be examined in other studies to confirm or refute this observation.

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PubMed2006

Association between cognitive function, behavioral syndromes and two-year clinical outcome in Chinese subjects with late-onset Alzheimer's disease.

OBJECTIVE: To examine associations between behavioral and psychological symptoms of dementia (BPSD), cognitive function and clinical deterioration over 2 years. METHODS: One hundred and four Chinese subjects with late-onset Alzheimer's Disease (AD) who presented to psychogeriatric clinics were followed for an average of 22.5 months. BPSD subgroups were categorized by latent class analysis using the Neuropsychiatric Inventory. Comprehensive cognitive profiles were performed with the Mattis Dementia Scale, the Hong Kong List Learning Test (HKLLT) and the Category Verbal Fluency Test. Interactions between cognitive function and behavioral syndromes were evaluated. Potential predictors for clinical deterioration were computed with logistic regression analysis. RESULTS: Three latent classes of subjects with similar behavioral syndromes were identified: Low BPSD (44%), Affective (32%) and Psychosis (24%) groups. Association between cognitive functions and BPSD was not significant. At follow-up, a higher proportion of subjects in the Affective (70%) and Low BPSD (49%) groups remained stable at the same Clinical Dementia Rating. Baseline scores in the "recognition" test of the HKLLT and age were significant predictors for "deceased" status at 2-year follow-up. CONCLUSION: The lack of association between behavioral syndromes and cognitive function suggests that these relatively independent dimensions of dementia should be examined individually for different prognostic significance.

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PubMed2006

Validation of the Chinese Challenging Behaviour Scale: clinical correlates of challenging behaviours in nursing home residents with dementia.

BACKGROUND: Behavioural and psychological symptoms of dementia (BPSD) are associated with considerable burden to patients with dementia and their caregivers. Formal caregivers in residential care settings face different challenges when delivering care. OBJECTIVE: This study aimed at assessing the clinical correlates of challenging BPSD using the Chinese version of the Challenging Behaviour Scale (CCBS) designed for residential care settings. METHODS: One hundred and twenty-five participants were recruited from three care-and-attention homes in Hong Kong. The CCBS was administered together with the Cantonese version of Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), Disability Assessment for Dementia (DAD) and Neuropsychiatric Inventory (NPI) to explore the relationships between challenging behaviour and important clinical correlates. RESULTS: The CCBS had good internal consistency (alpha = 0.86), inter-rater (ICC = 0.79) and test-retest reliability (ICC = 0.98). A four-factor structure is demonstrated by factor analysis: hyperactivity behaviours, hypoactivity behaviours, verbally aggressive and aberrant behaviours. Challenging behaviours were associated with male gender, cognitive impairment, functional disability, neuropsychiatric symptoms, and higher caregiver's workload. CONCLUSIONS: The CCBS is a valid and reliable measure to assess BPSD in residential care settings in local Chinese community. It is useful in evaluating the challenges faced by formal caregivers during daily care of the dementia patients.

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PubMed2005

Subjective memory complaints in Chinese subjects with mild cognitive impairment and early Alzheimer's disease.

BACKGROUND: Mild cognitive impairment (MCI) represents a transitional state between normal aging and dementia. However, there is inconsistent opinion as to the validity of subjective memory complaints as a criterion for diagnosis. OBJECTIVE: This study aimed to examine the potential significance of applying a short memory questionnaire in the assessment of Chinese subjects with MCI and early dementia. METHODS: Three hundred and six ambulatory Chinese subjects were recruited. Each participant completed a short memory questionnaire. They were also assessed with the Chinese versions of the mini-mental state examination (CMMSE), Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog), category verbal fluency test (CVFT) and span tests. Severity of cognitive impairment was evaluated using the Clinical Dementia Rating (CDR); subjects with CDR 0.5 were further classified into MCI not demented (MCIND) and MCI possible incipient dementia (MCIID) depending on the subscale scores of CDR. RESULTS: An increasing frequency of memory complaints with increasing CDR was observed (Kruskal Wallis test, chi square = 21.29, df 3, p < 0.001). With a cutoff of 3 or more memory complaints, the memory questionnaire demonstrated a sensitivity of 65.3% and 70.4% in identifying subjects with incipient and early dementia respectively. Significant associations between memory complaints and most cognitive test performance were found (Spearman's correlations, p < 0.01). Logistic regression analysis revealed that educational level, the memory questionnaire, ADAS-Cog total and delayed recall scores were significant predictors of MCIID status. CONCLUSIONS: The findings suggested that a short memory questionnaire is useful in the screening of MCI, particularly in subjects who already present with subtle functioning disturbances. Subjective memory complaints were significant correlated with objective performance of memory functions, reflecting the usefulness of memory complaints in the assessment of MCI.

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PubMed2005

Association between mind-body and cardiovascular exercises and memory in older adults.

OBJECTIVES: To compare the memory function of older adults who regularly practiced mind-body (MB) or cardiovascular (CV) exercises with that of those who did not engage in regular exercise. Older adults who engaged in both types of exercise were also included to examine the combined effects. DESIGN: Cross-sectional study between 2002 and 2003. SETTING: Older adults from a local community in Hong Kong. PARTICIPANTS: One hundred forty adults aged 56 and older. MEASUREMENTS: The Hong Kong List Learning Test was used to assess the memory of all participants. It is a clinically validated Chinese verbal-memory test that measures various aspects of memory processing, including learning, retention, and retrieval abilities. MB and CV exercises were defined using three dimensions: motion speed, emphasis on relaxing the mind, and conscious control of movement. RESULTS: Older adults who practiced MB or CV exercises demonstrated a similar level of memory function, and their learning and memory was better than that of individuals who did not exercise regularly. Those who practiced both types of exercises outperformed all other groups, even after corrected for the total hours of exercise. Although memory change across age was found in older adults who did not exercise, this trend was not observed in individuals who practiced MB exercises. CONCLUSION: Practicing both MB and CV exercises appears to have a combined effect that might help to preserve memory in older adults. In addition, MB exercises may be considered as an alternative training for older adults who cannot practice strenuous physical exercise.

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PubMed2004

Executive function impairment in community elderly subjects with questionable dementia.

BACKGROUND: The neurocognitive profile of community-dwelling Chinese subjects with 'questionable' dementia was studied. METHODS: One hundred and fifty-four ambulatory Chinese subjects were recruited from local social centers for the elderly. Each subject was examined using the Clinical Dementia Rating (CDR), the Cantonese version of the Mini-Mental State Examination (CMMSE), the Chinese version of the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), the Category Verbal Fluency Test (CVFT), digit and visual span tests, and the Cambridge Neurological Inventory. The neurocognitive profile of nondemented subjects (CDR 0) was compared with that of subjects with 'questionable' dementia (CDR 0.5). RESULTS: Subjects with 'questionable' dementia were older, and had lower educational levels and global cognitive assessment scores than the controls (CMMSE and ADAS-Cog; t tests, p < 0.001). In addition, they also had significantly lower scores in delayed recall, reverse span, verbal fluency tests and worse performance in complex motor tasks related to executive function (Mann-Whitney tests, p < 0.001). Logistic regression analysis revealed that ADAS-Cog, CVFT, and reverse visual span were significant predictors for the CDR of 'questionable' dementia. CONCLUSION: Aside from memory impairment, executive function deficits were also present in subjects with 'questionable' dementia. To identify groups cognitively at risk for dementia, concomitant assessments of memory and executive function are suggested.

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PubMed2004

Association between tumor necrosis factor-alpha promoter polymorphism and Alzheimer's disease.

Tumor necrosis factor-alpha (TNFalpha) gene polymorphisms have been reported to be associated with Alzheimer's disease (AD) in Caucasian populations. Three TNFalpha polymorphisms (-857, -863, and -1,031) were studied in a Chinese population. A high-risk TNFalpha haplotype (-1,031C-863C-857C) with an odds ratio of 2.54 (95% CI 1.37 to 4.79) for AD was identified. No interaction effect of APOE and TNFalpha genotypes was found, but both acted as important risk factors for AD.

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PubMed2004

Severe acute respiratory syndrome (SARS) in Hong Kong in 2003: stress and psychological impact among frontline healthcare workers.

BACKGROUND: The outbreak of severe acute respiratory syndrome (SARS) posed an unprecedented threat and a great challenge to health professionals in Hong Kong. The study reported here aimed at investigating the origin of stress and psychological morbidity among frontline healthcare workers in response to this catastrophe. METHOD: Self-administered questionnaires were sent to frontline healthcare workers in three hospitals. The General Health Questionnaire was used to identify psychological distress. Socio-demographic and stress variables were entered into a logistic regression analysis to find out the variables associated with psychological morbidity. RESULTS: The response rate was 40 %. Sixty-eight per cent of participants reported a high level of stress. About 57 % were found to have experienced psychological distress. The healthcare workers' psychological morbidity was best understood by the perceptions of personal vulnerability, stress and support in the workplace. CONCLUSION: These findings shed light on the need for hospital administrators to be aware of the extent and sources of stress and psychological distress among frontline healthcare workers during disease outbreak.

Adaptation, Psychological↗
PubMed2003

Validity and applicability of the Chinese version of community screening instrument for dementia.

The development of an educationally independent screening instrument for dementia is most valuable for epidemiological studies. The Community Screening Instrument for Dementia (CSI-D) was applied to 120 subjects, with 30 matched for age in each of the four groups of mild to moderately demented, depressed, low-education and high-education normal control subjects. The internal consistency and interrater reliability of CSI-D were satisfactory. Correlation with the ten-word-list learning task, a test sensitive to early dementia, was high. CSI-D could differentiate the demented from nondemented subjects, but not the high- from the low-education control group. Receiver operating characteristic analysis showed good test performance of CSI-D. In conclusion, the Chinese version of CSI-D is a valid, reliable and educationally independent screening instrument for dementia sensitive to detect early stage of the disease.

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PubMed2003

Progress of memory function after radiation therapy in patients with nasopharyngeal carcinoma.

The authors evaluated the late neurocognitive profile and progress of memory functions in 60 patients with primary nasopharyngeal carcinoma who had been treated with radiation therapy for more than 2 years. Forty had imaging evidence of temporal lobe injury (TLI-positive), and 20 did not (TLI-negative). The patients and 19 healthy control subjects, matched with the patients for age and educational level, underwent extensive memory assessments. Seventeen patients (10 TLI-positive, 7 TLI-negative) were reassessed after an average of 28 months for progress of memory functions. The patient groups performed significantly worse on most memory tests compared with the normal subjects. Patients with memory complaints had lower scores for verbal memory than those without such complaints. The TLI-positive and TLI-negative groups did not differ significantly from each other in cognitive performance. At follow-up, visual memory performance had deteriorated, while verbal memory remained more stable.

Adult↗
PubMed2002

Prevalence of dementia with Lewy bodies in an inpatient psychogeriatric population in Hong Kong Chinese.

OBJECTIVE: To find out the prevalence of dementia with Lewy bodies (DLB) in an inpatient psychogeriatric population in Hong Kong Chinese. METHOD: Clinical notes of all dementia patients admitted to an inpatient psychogeriatric unit between 1 January and 31 December 2000 were reviewed to retrieve information on various subtypes of dementia that have been diagnosed prospectively using NINCDS-ARDRA, NINDS-AIREN, CDLB and DSM-IV by qualified senior psychogeriatricians. RESULT: There were only three cases of dementia with Lewy bodies out of 102 dementia inpatients, giving a prevalence rate of 2.9% over a two-year period. CONCLUSION: The prevalence rate of dementia with Lewy bodies is remarkably lower than figures reported in western studies. Further evaluation using better sampling frame and better-validated diagnostic gold standard is required. Ethnically related biological factors may be implicated to explain the preliminary low prevalence rate in Chinese population.

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PubMedDate not supplied

Apolipoprotein epsilon-4 allele and the two-year progression of cognitive function in Chinese subjects with late-onset Alzheimer's disease.

BACKGROUND: Although the significance of apolipoprotein E4 (Apo E4) in Alzheimer's disease (AD) has been well established in Caucasian populations, its role in determining the rate of cognitive decline in other ethnic groups has yet to be determined. This study examined the two-year progression of cognitive decline and its association with Apo E4 allelic status in a group of Chinese elderly subjects with AD. METHOD: One hundred and four Chinese subjects with mild and moderate AD as assessed by the Clinical Dementia Rating (CDR 1 and 2) were followed up at a mean (SD) duration of 22.53 (5.21) months. The rate of cognitive decline and its association with Apo E4 allelic status was evaluated RESULTS: At follow-up, 74 (73 percent) subjects were reassessed. Forty-nine remained stable at the same CDR and 25 had deteriorated. The mean (SD) deterioration in the Mini-Mental State Examination (MMSE) was 2.52 (4.38) and in the Mattis Dementia Rating Scale (DRS) was 9.03 (14.98) (paired t-test, p < 0. 001). There was no significant difference in the baseline MMSE and DRS scores between the "stable", "deteriorated", or "deceased" groups. Mildly demented subjects with the Apo E4 allele were more likely to have deteriorated to a more severe CDR than subjects without the Apo E4 allele (Pearson chi2 = 5.72, df 1, p = 0.017, Odds ratio = 6.3, CI 1.3 to 30.53). CONCLUSION: The presence of the Apo E4 allele may influence the rate of cognitive deterioration, particularly in subjects with mild AD.

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