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C Brayne

Publications and source records attributed to C Brayne.

90 records · Page 5Linked to original sources
PubMed1992

Epidemiologic approach to the study of dementing diseases: a nested case-control study in European incidence studies of dementia.

In 1994 several European studies will have available risk factor information on incident cases of dementia collected in prospective community-based studies. These centers will collaborate in a nested-case control study based on the pooled cases and a sample of the non-diseased respondents. This paper describes the general design and the risk factors to be studied in a European nested case-control study of Alzheimer's disease and vascular dementia.

Aged↗
PubMed1991

Frequency and distribution of Alzheimer's disease in Europe: a collaborative study of 1980-1990 prevalence findings. The EURODEM-Prevalence Research Group.

We reanalyzed and compared current prevalence estimates of Alzheimer's disease in Europe. Studies characterized as follows qualified for comparison: dementia defined by the Diagnostic and Statistical Manual for Mental Disorders, 3rd edition, or equivalent criteria; Alzheimer's disease diagnosed by the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association or equivalent criteria; case-finding through direct individual examination; appropriate sample size; and inclusion of institutionalized persons. Of the 23 European surveys of dementia considered, six fulfilled the inclusion criteria. When age and sex were considered, there were no major geographic differences in the prevalence of Alzheimer's disease across Europe. Overall European prevalence (per 100 population) for the age groups 30 to 59, 60 to 69, 70 to 79, and 80 to 89 years was, respectively, 0.02, 0.3, 3.2, and 10.8. Prevalence increased exponentially with advancing age and, in some populations, was consistently higher in women. Prevalence remained stable over 15 years in one study.

Adult↗
PubMed1991

The prevalence of vascular dementia in Europe: facts and fragments from 1980-1990 studies. EURODEM-Prevalence Research Group.

We selected, reanalyzed, and compared data from current prevalence studies of vascular dementia in Europe. Inclusion criteria were: dementia defined by the Diagnostic and Statistical Manual for Mental Disorders, edition 3, or equivalent criteria; case finding through direct individual examination; appropriate sample size; and inclusion of institutionalized persons. Mixed dementia was combined with vascular dementia. Of the 23 surveys of dementia considered, five fulfilled the inclusion criteria. Age-specific prevalence varied more widely for men than for women; differences were greater in older ages. The prevalence increased steeply with advancing age in all countries, and was generally higher in men; it declined over 15 years in the age class of 80 to 89 years in one Swedish population. Within populations, Alzheimer's disease was generally more common than vascular dementia. Unfortunately, prevalence studies of vascular dementia are limited in Europe and worldwide, and their comparison is impeded by the lack of common diagnostic criteria.

Aged↗
PubMed1991

The prevalence of dementia in Europe: a collaborative study of 1980-1990 findings. Eurodem Prevalence Research Group.

To obtain age- and gender-specific estimates of the prevalence of dementia in Europe and to study differences in prevalence across countries, we pooled and re-analysed original data of prevalence studies of dementia carried out in some European countries between 1980 and 1990. The study followed these steps: census of existing datasets, collection of data in a standardized format, selection of datasets suitable for comparison, comparison of age and gender patterns. From the 23 datasets of European surveys considered, 12 were selected for comparison. Only population-based studies in which dementia was defined by DSM-III or equivalent criteria and in which all subjects were examined personally were included. Studies in which institutionalized subjects were not investigated were excluded. Age- and gender-specific prevalences were compared within and across studies and overall prevalences were computed. Although prevalence estimates differed across studies, the general age- and gender-distribution was similar for all studies. The overall European prevalences for the five-year age groups from 60 to 94 years, were 1.0, 1.4, 4.1, 5.7, 13.0, 21.6 and 32.2%, respectively. In subjects under 75 years the prevalence of dementia was slightly higher in men than in women; in those aged 75 years or over the prevalence was higher in women. The prevalence figures nearly doubled with every five years of increase in age.

Adult↗
PubMed1991

The EURODEM collaborative re-analysis of case-control studies of Alzheimer's disease: implications for public health.

In the EURODEM pooling and re-analysis of case-control studies of Alzheimer's disease it has been possible to examine putative risk factors with increased power to detect associations. The fundamental problems of case and control selection persist, such as use of prevalent cases, selection through contact with specific services, difficulties of control choice. Risk factors such as family history and head trauma are shown again, although the biases introduced in collection of exposure data could still account for these findings. Other associations which are shown, such as smoking may be accounted for by factors related to survival and use of prevalent cases. The direct public health implications of these findings are limited. Intervention based on many of the associations found in this re-analysis would have relatively low impact on overall rates of Alzheimer's disease because of the small proportion of the population exposed. The total public health impact of any such intervention would be also limited according to the contribution which Alzheimer's disease makes to overall rates of dementia. Improvement of cardiovascular indices may improve the cerebrovascular status of the population, possibly reducing the incidence of vascular dementia. Other broad strategies to maintain health and function would seem prudent, but specific recommendations to reduce the incidence of Alzheimer's disease, or to slow progression of the disorder cannot be recommended on the basis of these re-analyses. It is clear that more research is needed to understand the risks of different pathologies related to Alzheimer's disease as well as dementia and cognitive change generally in the population.(ABSTRACT TRUNCATED AT 250 WORDS)

Alzheimer Disease↗
PubMed1990

The association of education and socioeconomic status with the Mini Mental State Examination and the clinical diagnosis of dementia in elderly people.

The distribution of scores in the Mini Mental State Examination (MMSE) of women aged 70-79 years from a rural area of Cambridgeshire is reported. Increasing age, lower socioeconomic group and less education were all found to be associated with lower scores on MMSE. Of these, only increasing age was significantly related to an increase in the diagnosis of dementia.

Aged↗
PubMed1990

Serum creatine kinase BB isoenzyme levels in an epidemiological study of dementia and cognitive impairment.

It has been suggested that serum creatine kinase levels might be useful in the investigation of dementia. In this study serum creatine kinase BB (CKBB) isoenzyme levels were investigated in a community population of elderly women aged 70 to 80 years. Normative data for this group were compared with the findings in younger age groups. No relationship was found between levels of CKBB and level of dementia, or with the specific clinical diagnosis of senile dementia of the Alzheimer type, although a weakly positive relationship was found between CKBB and 3 cognitive scales.

Age Factors↗
PubMed1990

Estimation of verbal intelligence in an elderly community: a prediction analysis using a shortened NART.

Estimation of premorbid IQ is useful for estimating true cognitive decline in dementia. The National Adult Reading Test-NART (Nelson, 1982)-has been shown to estimate premorbid IQ in hospital patients. NART is potentially of use in epidemiological studies. However, asking community elderly people to read a list of irregular and difficult words can cause distress. This paper explores the possibility of administering only a part of the NART. On the basis of scores on the first half of the test from an elderly rural community sample (N = 316), a regression equation has been developed to predict performance on the second half of the test. It was built using the scores of half the population free from clinical diagnoses and tested on the other half. It was also applied to a demented group and a depressed group from the same population. Total NART scores predicted in this way were highly significantly correlated with the actual NART score for all groups. Recommendations about the use of this shortened test are made.

Aged↗
PubMed1990

Estimation of verbal intelligence in an elderly community: an epidemiological study using NART.

The National Adult Reading Test (NART) has become widely used by psychologists in clinical practice as part of the assessment of cognitive decline in organic mental disorders. Some normative data have been presented on community samples from a wide range of ages, but little is known of the instrument's performance in true community samples of the elderly. This study presents data on NART from an epidemiological study of dementia and cognitive impairment in elderly women. The contribution of educational level and social class to performance on the scale was examined. NART was found to be strongly related to current level of cognitive function as measured by the Mini Mental State Examination and CAMCOG-the neuropsychological battery of the Cambridge Examination for Mental Disorders in the Elderly. For most subjects in the community the NART was found acceptable as a measure of premorbid intelligence.

Aged↗
PubMed1989

An epidemiological study of dementia in a rural population of elderly women.

A study of 365 women aged 70-79 in a rural community was carried out using the Cambridge Examination of Mental Disorders in the Elderly (CAMDEX). Prevalence rates of dementia are reported by severity for the 70-74 and 75-79 age groups. Differential diagnosis was made according to CAMDEX guidelines. Senile dementia of Alzheimer type accounted for half the dementia cases. The prevalence rates overall did not differ from those reported in other recent studies, but the rates for levels greater than mild/moderate were lower, despite the inclusion of subjects in institutions.

Aged↗
PubMed1988

Normal ageing, impaired cognitive function, and senile dementia of the Alzheimer's type: a continuum?

There is little evidence to support the view that senile dementia of the Alzheimer's type (SDAT) is distinct from the normal ageing process. The changes in brain function found in normal ageing, benign senescent forgetfulness, and SDAT can be seen as a continuum, which may reflect a single underlying process. The failure to account for this possibility in research design may explain why few risk factors for SDAT have been identified.

Age Factors↗
PubMedDate not supplied

Examination of phosphorylated tau protein as a PHF-precursor at early stage Alzheimer's disease.

Hyperphosphorylated tau protein which can be isolated on the basis of insolubility in 1% sarkosyl (A68-tau fraction) is thought to represent a precursor pool for PHF assembly, associated histologically with neuritic pathology, which feeds into a more resistant tangle-associated PHF pool via cross-linking and proteolysis. We examined these predictions at the earliest detectable stages of neurofibrillary pathology. We report that there is no evidence that neuritic pathology represents an early pathologic stage, no evidence of an association between neuritic pathology and phosphorylated tau, no evidence of selective accumulation of phosphorylated tau at early stages of pathology, and no evidence for a precursor/product relationship between phosphorylated tau and PHFs during progression of pathology. We conclude that altered phosphorylation is a secondary process affecting 5% of PHFs and does not explain PHF assembly in Alzheimer's disease.

Aged↗
PubMedDate not supplied

Quantitative analysis of tau protein in paired helical filament preparations: implications for the role of tau protein phosphorylation in PHF assembly in Alzheimer's disease.

In Alzheimer's disease, there is a major redistribution of the tau protein pool from soluble to PHF-bound forms. PHF-bound tau can be distinguished from normal tau by acid reversible occlusion of a generic tau epitope in the tandem repeat region and characteristic sedimentation in the if-II protocol developed in this laboratory. We show that 85% of tau bound in the PHF-like configuration can be recovered in the if-II PHF-fraction. Less than 1% of this material was phosphorylated at the mAb AT8 site in aged clinical controls or in cases with minimal or mild dementia. Of tau phosphorylated at the mAb AT8 site, only 12% was found to co-sediment with PHFs. These low levels could not be explained by postmortem dephosphorylation. As more than 95% of PHF-tau is not phosphorylated, even at early stages of pathology, it is misleading to use the terms "PHF-tau" and "phosphorylated tau" as though they were synonymous, particularly as this implies a pathogenetic role which phosphorylation need not have.

Alzheimer Disease↗
PubMedDate not supplied

Vascular risks and incident dementia: results from a cohort study of the very old.

The contribution of vascular pathology to the manifestation of dementia and the importance of vascular risk to measures of cognitive function is being increasingly recognized. In particular, confirmation of this risk points towards approaches for prevention in large sections of the population. Information on determinants of incident dementia is increasing, but still relatively few studies of risk have been based on incident cases of dementia in very elderly populations. In this study based on incident cases of dementia in a population aged 75 and over, vascular risks were obtained from informants of the respondents with incident dementia. When compared with controls the factors associated with incident dementia were history of heart attack (odds ratio 2.9), transient ischaemic attacks (4.8), cerebrovascular accidents (3.4), family history of first-degree relatives with dementia (4.0), and occupational exposure to vibrating instruments (1.4). If only Alzheimer's disease, clinically diagnosed, was included, diabetes (1.4) and a history of dementia in first-degree relatives (6.6) emerged. Thus, vascular risk continues to be of importance in the oldest age groups.

Aged↗
PubMedDate not supplied

Apo E and Apo CI loci are associated with dementia in younger but not older late-onset cases.

Numerous groups have confirmed that apolipoprotein E allelic variation accounts for a proportion of the genetic risk for late-onset Alzheimer's disease (AD). However, there is a paucity of data on the impact of this locus on the overall risk of dementia (as opposed to AD) in the elderly. Most studies have ascertained specifically AD cases from hospital clinics or brain banks and many demented cases have vascular dementia or mixed AD and vascular pathology. We have examined the closely linked apo E and apo CI loci in demented cases and non-demented controls from two community-based aged Cambridgeshire populations: the rural Ely population (cohort 1) comprised 60 pairs of demented and non-demented elderly individuals, with a mean age of 84.2 years (SD = 6.11); the Cambridge city population (cohort 2) comprised 81 pairs all aged over 84 with a mean age of 87.7 years (SD = 2.9). The younger Ely cohort showed significant allelic associations with dementia at the apo E and apo CI loci, which were not replicated in the older Cambridge cohort. These data suggest the possibility of age-dependent penetrance for different candidate genes in late-onset dementia. We propose a number of explanations to account for the stronger associations we observed between dementia and apo CI, compared to the neighbouring apo E locus. Our data are compatible with the possibility that specific alleles or genotypes may confer different risks for overall dementia, compared to AD.

Adolescent↗
PubMedDate not supplied

Apolipoprotein E genotype, vascular risk and early cognitive impairment in an African Caribbean population.

A reduced risk of Alzheimer's disease (AD) associated with the apolipoprotein E (APOE) epsilon4 allele is reported in populations of African origin. In order to clarify possible reasons for this, we examined the association between APOE genotype and early cognitive impairment in a community-based African Caribbean UK population aged 55-75 years. APOE genotype was available for 202 participants, 57 (28%) of whom were classified as having relative cognitive impairment on a battery of neuropsychological tests. Cognitive impairment was negatively associated with epsilon2 and positively but more weakly associated with epsilon4. Effects of both alleles increased markedly after age 70. The effect of epsilon4 was increased in combination with hypertension, diabetes or lower educational attainment, but these factors did not influence epsilon2 effects. Cholesterol and triglyceride levels partially explained effects of epsilon2, but did not account for those of epsilon4. A reduced association between epsilon4 and later AD in populations of African origin is unlikely to be explained by reduced cognitive effects or by differential mortality. However, it may be accounted for by vascular comorbidity. The different patterns of association between epsilon2 and epsilon4 alleles suggest different pathways of effect.

Black or African American↗
PubMedDate not supplied

Apolipoprotein E genotype in the prediction of cognitive decline and dementia in a prospectively studied elderly population.

An increased apolipoprotein E (ApoE) type epsilon 4 allele frequency is associated with both sporadic and familial late-onset Alzheimer's disease (AD). The age of onset of disease in patients homozygous for the epsilon 4 allele appears to be decreased by approximately 15 years compared with E2/3 individuals. In order to assess the influence of this allele on both dementia and cognitive decline in the elderly we have determined the ApoE genotype of 150 individuals over the age of 75 years who have taken part in a longitudinal study. Homozygosity for the epsilon 4 allele was rare. Of the 2 homozygotes, 1 was severely demented but the other did not receive a clinical diagnosis of dementia. The latter individual did demonstrate marked cognitive decline over a 28-month period. There was a consistent association between the presence of an epsilon 4 allele and both the clinical diagnosis of dementia and cognitive decline. These findings confirm a genetic heterogeneity in late-onset sporadic AD and prompt caution in the use of ApoE genotype to predict an elderly individual's susceptibility to either dementia or cognitive decline.

Aged↗