Dementia (Basel, Switzerland)最新文献

We studied the effects of 40 and 80 mg/day of tacrine on patients with probable Alzheimer's disease (AD) in an 8-week, randomized, double-blind, placebo-controlled crossover trial with an enriched-population design. In the initial dose titration phase, an intent-to-treat analysis showed significantly more improvement with 80 mg/day of tacrine than placebo. In the subsequent crossover trial that included only 'responders', no significant improvement was observed with tacrine, whether or not it was given with lecithin. We found that individualized dose titration and enrichment strategies were not helpful and had the effect of reducing the power of the study. In the dose titration phase of this study we found that more impaired subjects were as likely to improve as those who were less impaired, suggesting that tacrine should be further investigated in more severely demented AD patients.

Apolipoprotein E (apoE) epsilon 4 allele frequency among Alzheimer's disease (AD) patients is increased compared to control subjects and is influenced by the presence of other genetic factors and age at symptom onset. We examined the relationship between age at AD symptom onset and apoE by comparing the apoE epsilon 4 allele frequency of normal, elderly control subjects (n = 107) to that in AD patients (n = 123), divided into four age-at-onset periods. Additionally, the distribution of symptom onset ages of AD patients with and without apoE epsilon 4 alleles was determined. We observed increased apoE epsilon 4 allele frequencies between the AD onset ages of 55 and 75 years, but not at the extremes of onset ages (i.e. onset between 45 and 54 years of age and after age 75). Our data suggests that having an apoE epsilon 4 allele increases the likelihood that AD patients will develop symptoms in the middle range of onset ages. At the extremes of AD onset ages, non-apoE factors, including other genetic factors and age, are more important determinants of risk of developing AD.

Serum amyloid P component (AP) is a normal plasma constituent that is observed in senile plaques and neurofibrillary tangles in brains of Alzheimer's disease (AD) patients. In this study we have evaluated the AP levels in sera of 16 patients with AD and in 16 control subjects by enzyme-linked immunosorbent assay. The AP level was 22.4 +/- (SD) 7.0 micrograms/ml in the AD group and 34.4 +/- (SD) 6.6 micrograms/ml in the control group. The AP level in the AD group was significantly lower than that of the control group (p < 0.01). In the control group, there was no correlation between AP levels and age. Our results suggest that the production of AP by the liver (hepatocytes), thought to be the only source, may be suppressed in AD patients and that the deposition of AP in senile plaques and neurofibrillary tangles is not due to its overproduction.

Regional cerebral glucose metabolism was surveyed in 37 Alzheimer's disease (AD) patients and 21 normal controls using positron emission tomography. Where possible, brain regions were specified according to their neurobehavioral function rather than as anatomically demarcated structures. Absolute metabolic values revealed significant differences (p < 0.05) between AD patients and controls for whole brain and the more superior supratentorial brain slices. Normalized values (region/brain stem) showed the most striking declines (p < 0.001) in the association cortex (heteromodal region -21%; unimodal region -19%) and the primary sensory-motor cortex (-13%), with motor, auditory, and visual areas more affected than somatosensory areas. Limbic and paralimbic systems were equally affected (-14%; -11%; p < 0.001). Thalamus, striatum, cerebellum and brain stem were minimally or not affected. Neurobehaviorally defined hypometabolic regions largely parallel affected areas noted in anatomic and previous metabolic studies, with the possible exception of metabolic deficits in the primary sensory-motor complex. Conceivably, brain areas unaffected morphologically by the pathophysiological processes of AD may become dysfunctional due to a disruption of connectivity between regions.

Reported findings regarding sleep and sleep disorders in the elderly often conflict. Differences in results across studies may arise from selection of subjects, definitions and recording conditions. Our purpose was to test a method to study elderly, both healthy and demented, under the most natural conditions, without disturbing a fragile sleep. Using clinical parameters and a non-disturbing recording method, we evaluated sleep quality in patients with carefully diagnosed dementia and compared the results to a group of healthy subjects between 50 and 70 years of age. Healthy subjects awoke less and had more quiet sleep than patients, while in patients a tendency for delayed sleep latency and more active sleep was observed. Consistent with previous investigations, sleep-related respiratory disorders (SRRD) were more common in patients than in the matched control group, and periodic breathing appeared only among patients. SRRD, of both obstructive and central types, were only mild, with periodic breathing dominating only among patients. Most of the desaturations were less than 10%. We did not observe respiration of the Cheyne-Stokes type. Patients had more sleep-related movement disorders (SRMD), particularly with increase of twitches and long movements. Periodic movements were not significantly increased among the patients. The method, and the data obtained may be useful for practitioners dealing with sleep disorders in geriatric populations. In the elderly, interactivity between sleep, SRRD and SRMD may be bidirectional and as elderly and demented subjects might have a distorted homeostatic sleep response, SRRD and SRMD, even in a mild form, may cause sleep disruption and worsen dementia.

This study investigated differential patterns of performance by 40 Alzheimer's disease (AD) patients on standardised letter and category fluency tests. The performance of 24 age and education matched controls was used to classify patients as relatively more letter fluency impaired (L < C, n = 15) or more category fluency impaired (C < L, n = 25), and clinical features distinguishing these patient subgroups were investigated. Category performance was equally impaired in both patient subgroups, whereas the L < C subgroups were particularly impaired on letter fluency. The subgroups differed significantly in duration of illness (24 months for L < C group, 47 months for C < L group; t = 2.69, p = 0.01) but did not differ in global dementia severity, age, education, general language ability, or functional status. Data on annual rate of change (ARC) on the Mini-Mental State Examination were available for 26 patients. While not statistically significant, subgroup ARC differences were suggestive of more rapid decline in the L < C patients, consistent with the finding of shorter duration of illness in this group. Word fluency tests may have potential as early predictors of rate of progression in AD.

Glial fibrillary acidic protein (GFAP) is the structural protein of the astroglial intermediate filament that forms the morphological basis of astrogliosis. In the present study, GFAP concentrations in cerebrospinal fluid were measured in patients with various dementia diseases. A significant correlation between GFAP and age was found both in the total dementia group and in the controls. Covariance analysis with GFAP as dependent variable and age and albumin ratio as covariates followed by multiple group comparisons showed that, with regard to GFAP levels, the controls (n = 39) differed significantly from the patients with vascular dementia (n = 20; p < 0.05), senile dementia of the Alzheimer type (n = 29; p < 0.05), and 'pure' Alzheimer's disease (n = 8; p < 0.05), but not from those with frontal lobe dementia (n = 5).

Pre- and postsynaptic elements of the 5-hydroxytryptamine (5-HT, serotonin) system were studied in a control group and in patients with vascular dementia (VAD). The 5-HT uptake site was used as a presynaptic marker for 5-HT terminals and 5-HT1A and 5HT2 receptors were used as postsynaptic markers. The binding sites were quantified with radioligand binding techniques, where the radioligands used were [3H]paroxetine, [3H]8-OH-DPAT and [3H]ketanserin, respectively. The presynaptic uptake site was studied in frontal and temporal cortices and caudate nucleus. 5-HT1A and 5-HT2 receptors were studied only in frontal and temporal cortices. There were no differences between control and VAD groups in any of the regions investigated with respect to the number of binding sites (Bmax) and binding affinity (Kd). This indicates that both pre- and postsynaptic parts of the 5-HT system are intact in these brain areas in VAD.

We quantified the synaptic density in the outer molecular layer of the hippocampal dentate gyrus. Autopsy material from 9 individuals with Alzheimer disease (AD) were compared to 10 age-matched, postmortem-matched controls without dementia, using standard electron microscopy. Statistical analyses showed a significant change in the density of synapses between controls and AD subjects. There was a significant decline in the width of the entire molecular layer in the AD material. Synaptic density showed a significant correlation with synaptic apposition length in both AD and control groups. As the number of synapses declined, the synaptic apposition length increased. The decline in density of synapses in the AD group might reflect the degree of neuronal loss in the entorhinal cortex. Such a loss in synaptic connectivity could play a key role in memory-related problems associated with AD.

The prevalence of clinical dementia was assessed in three age groups of patients with Down syndrome in the county of Aarhus, Denmark: Group I: 14-16 years (n = 13), group 2: 23-29 years (n = 34), group 3: 50-60 years (n = 25). Seventy-two (85%) of 85 patients participated. Caregivers were interviewed and a neurological examination was performed. An EEG was recorded in 50 patients. Definite clinical dementia was defined as an acquired and progressive decline in 4 or more out of 17 items that are considered to indicate dementia in Down syndrome. Possible dementia was considered when 1-3 items were affected. Six (24%) in group 3 had definite clinical dementia. A further 6 patients in group 3 and 2 (6%) in group 2 had possible dementia. This is the first population-based study with a clinical assessment of the prevalence of dementia in Down syndrome.