摘要:

We considered whether general practitioners should examine all older patients over a certain age for cognitive impairment in screening for early dementia. We invited presentations from key experts, selectively reviewed the literature, and developed a consensus statement. The efficacy of and benefits from unselective use of cognitive testing and informant questionnaires for detecting early dementia in older patients attending general practice are limited. Positive predictive values of cognitive screening for dementia are less than 50%, even for older patient populations. Higher values may be obtained by testing patients who have a relevant history of cognitive or functional decline. What ever procedures are adopted for screening older general practice attenders for cognitive impairment or early dementia, investigation is still required into the relative merits of different health professionals performing the screening, the positive and negative effects on patients and their families, and the cost-benefit ratio. The majority view of workshop participants was that cognitive testing should occur for older patients when there is a reason to suspect dementia. Testing may occur in an individual considered to be at risk because of an informant history of cognitive or functional decline, clinical observation, or, sometimes, very old age. No single instrument for cognitive screening is suitable for global use. Screening programs must be supported by training and supplemented by education for professionals and families in management of dementia.

ISSN:0893-0341    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

In this study, we examined the association between benzodiazepine use and the occurrence of Alzheimer disease and vascular dementia. The study was based on longitudinal data from a case-control study of 668 individuals aged 75 and older. The elderly were examined extensively by physicians, and family interviews were assessed. Dementia diagnosis was made by using DSM-III-R criteria. Individuals with a history of continuous use of benzodiazepines (BDZ+) were compared with nonusers (BDZ-), with respect to the incidence of Alzheimer disease or vascular dementia at follow-up 3 years later. It was found that there was a significantly lower incidence of Alzheimer disease in the BDZ+ group than in the BDZ- group. This negative association remained significant when controlling for age, gender, level of education, use of nonsteriodal antiinflammatory drugs, and estrogens. These results suggest that benzodiazepines may have protective effects against the disease.

ISSN:0893-0341    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Individuals with Alzheimer disease (AD) often forget how to perform everyday activities. To understand better this type of memory loss, the effects of familiarity and temporal organization on memory for event schemas was investigated in college students, elderly controls, and individuals with AD. Participants were asked to read short stories describing common activities. Both recall and recognition memory were assessed immediately after reading the story. The number of items correctly remembered and the error types were recorded and analyzed. Both familiarity and temporal organization were found to play a role in memory for event schemas. All groups remembered the most information when the stories were familiar and sequentially organized. Elderly participants were more likely to remember items associated with, but included in, the stories than were the other groups. The AD group was the only group to recall or recognize items not associated with the story. It was concluded that event schema memory in AD participants is moderated by the same factors that influence memory in healthy young and elderly participants. These results suggest that individuals with AD will be best able to perform common everyday activities when they are familiar and when daily activities follow a predictable sequential pattern.

ISSN:0893-0341    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Data on superoxide dismutase (SOD) activity in the cerebrospinal fluid (CSF) of patients suffering from dementia (n= 32) as compared with a control group (n= 58), a Parkinson disease (PD) patient group (n= 12), and a group of individuals suffering from epilepsy (n= 13) are presented. SOD activity was determined by electron spin resonance spectrometry using the spin trap method. No significant correlation was found between CSF SOD activity and age in the control group. In addition, CSF SOD activity was not gender dependent. One-way analysis of variance showed a highly significant between-groups effect for the CSF SOD activity and specific CSF SOD activity of the four major groups (p= 0.0008). Post hoc comparison (Fisher PLSD test) revealed significant differences between the control group and the total dementia group (p< 0.001), between the dementia group and the epilepsy group (p< 0.01), and between the dementia group and the PD group (p< 0.05). The CSF of patients with PD or epilepsy showed a similar SOD activity as the CSF of control patients. In addition, CSF SOD activity levels were significantly lower in the total dementia group (p= 0.002) and in the group with dementia of the Alzheimer type (DAT) (p= 0.001) than in the dementia age-matched control group. No significant difference was found for CSF SOD activity levels between the control group and the non-DAT dementia group. This result corresponded with a reduction of CSF SOD activity in the total dementia group, DAT subgroup, and non-DAT subgroup of 37, 43, and 22%, respectively. No significant correlation between the Mini-Mental State Examination score and CSF SOD activity was found in DAT. The lowered CSF SOD activity in Alzheimer disease, as demonstrated here, may reflect impaired radical defense mechanisms and may have possible pathophysiological significance.

ISSN:0893-0341    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

To evaluate the influence of the apolipoprotein E (ApoE) 4 allele on the age at which Alzheimer-like lesions appear in the brain, we analyzed the degree of cerebral β-amyloidosis and neurofibrillary tangle formation in the hippocampal formation and adjacent cortical areas 28, 27, and 36 of persons who had died between the ages of 50 and 93 years and who had shown no signs of clinical dementia. The occurrence of the three common polymorphisms of the ApoE gene in this sample of 147 routine autopsy cases from eastern Germany was comparable to previously reported values in European and North American populations: ApoE2/2, 0.7%; ApoE±2/3, 14.3%; ApoE±2/4, 4.1%; ApoE±3/3, 56.5%; ApoE±3/4, 22.4%; and ApoE±4/4, 2.0%. Nondemented persons carrying the ApoE±4 allele were significantly more likely to have senile plaques, diffuse amyloid deposits, cerebrovascular amyloid, and neurofibrillary tangles than were those lacking ±4. Comparing the two largest ApoE subgroups, ApoE±3/3 and ApoE±3/4, the relative increase in the occurrence of β-amyloid in the ±3/4 group was evident by the mid-60s, with the relative increase in neurofibrillary tangles in this group emerging slightly earlier. The ApoE±2 allele appears to delay the appearance of the lesions somewhat. We conclude that ApoE±4 promotes the early appearance of β-amyloid and neurofibrillary tangles in the elderly and that the increased frequency of these lesions is related to the higher risk of Alzheimer disease in persons bearing the ApoE±4 allele.

ISSN:0893-0341    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The ±4 allele atAPOE, the polymorphic locus for apolipoprotein E, increases the risk of Alzheimer disease (AD), especially among those with the homozygous ±4/±4 genotype. In family studies, ±4 homozygotes typically develop AD at 55–75 years, an age range when AD is otherwise relatively infrequent. Population-based studies of the AD risk associated with allele ±4 (and especially with genotype ±4/±4) are limited in number, and most such studies have included few AD cases between the ages of 55 and 75 years. In a large population-based twin registry, the screening of 12,709 men who were 62–73 years old yielded 38 prevalent cases of AD whose onset age ranged from 54 to 73. Genotype atAPOEwas determined for 37 of these cases and, independently, for a similarly aged probability sample of 344 men from the same registry. The ±4 allele frequencies among the AD cases and the population samples were 0.39 and 0.15, respectively. The odds ratios (ORs) for AD were 17.7 for genotype ±4/±4 versus ±3/±3 and 13.8 for ±4/±4 versus all remaining genotypes. By contrast, the ORs with heterozygous ±4/±3 were only 2.76 versus ±3/±3 and 2.01 versus all genotypes other than ±4/±3 (pfor homozygote vs. heterozygote ORs = 0.002). The estimated etiologic fraction for AD with homozygous ±4 among men in their mid-50s to mid 70s is therefore 0.20; for the much more common heterozygous genotype ±4/±3, the fraction is 0.18. In combination with other studies that have adjusted statistically for age, these results suggest that the effect of the ±4 allele dose is neither linear nor homogeneous for age. Homozygous ±4/±4 appears to confer an extreme risk of AD at the age when onset with this genotype is most likely. These results are consistent with the view that individual genotypes modify risk by predisposing to substantially different distributions of AD onsets.

ISSN:0893-0341    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The authors examined whether the ±4 allele might be associated with dementia in Parkinson disease (PD), given that the dementia of PD shares neuroanatomic and neurochemical features with Alzheimer disease (AD) and that many recent studies have found a high prevalence of the ±4 allele of apolipoprotein E (ApoE) in AD. The authors examined patients with PD (n= 125, 47 demented) and unrelated controls (n= 93) using a short mental test. DNA was obtained from blood leukocytes. The relevant portion of the apolipoprotein E (ApoE) gene was amplified by polymerase chain reaction, and the ±4 allele was identified using a restriction enzyme. The frequency of the ApoE ±4 allele in demented patients with PD (14%) was not greater than that in nondemented patients (17%), whereas patients with PD as a whole showed a trend toward a higher ±4 allele frequency (16%) than age-matched controls (10%,p= 0.07). The ±4 allele frequency in nondemented patients with PD was significantly higher than in controls (p= 0.055). These results and the meta-analysis of four published reports fail to support the hypothesis that the ±4 allele is associated with dementia in PD.

ISSN:0893-0341    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

As a preliminary part of a longitudinal clinical study of carriers of the Swedish amyloid precursor protein (APP) 670/671 mutation, 13 members of a family were investigated with magnetic resonance imaging (MRI) brain volumetry and single photon emission computed tomography (SPECT) cerebral blood flow (CBF) measurements. Five of the family members were mutation carriers; eight were not carriers. Two carriers were younger than 40 years of age and had no evidence of cognitive dysfunction or structural or functional brain changes. One carrier with 4 years to expected disease onset showed poor performance in episodic memory tests and also slightly low temporal lobe CBF, although there were no clearly abnormal findings. One carrier with mild Alzheimer disease (AD) had no clear structural brain changes, although CBF measurements showed clear reduction of temporal lobe CBF. One carrier with severe AD had both temporal lobe atrophy and CBF reduction. This indicates that in carriers of the APP 670/671 mutation, reduction of regional CBF is more severe than regional atrophy. The clearest change related to development of clinical AD was a reduction of CBF in the basal and lateral temporal lobes. Further longitudinal studies of these subjects are needed to confirm these preliminary findings, which might provide important data regarding early brain changes in AD.

ISSN:0893-0341    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Forty-seven patients with probable Alzheimer disease (AD) completed a 6-month double-blind study to compare metrifonate with placebo. The Alzheimer Disease Assessment Scale cognitive subscale score of the metrifonate group treated to a 50–70% inhibition of red blood cell acetylcholinesterase activity differed significantly from the placebo group score by 1.8 points (p< 0.03) due to a deterioration in cognitive performance in the placebo group (p< 0.01). Statistically significant deterioration also occurred in the Mini-Mental State Examination scores (p< 0.01) in the placebo-treated group. Adverse effects were uncommon and did not require adjustment of the dose of metrifonate or discontinuation of treatment. These findings extend our previous report of a favorable effect of metrifonate on cognitive symptoms in AD by showing clinical, not only statistical, significance.

ISSN:0893-0341    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0893-0341    

出版商:OVID    

年代:1998

数据来源: OVID