老年痴呆与血浆同型半胱氨酸水平关系的临床研究

目的:探讨血浆同型半胱氨酸(homocysteine,Hcy)水平与老年痴呆的相关性。方法:应用全自动生化分析仪以循环酶法检测90例老年痴呆患者的血浆Hcy浓度,并与30例非痴呆患者作为同龄对照组血浆Hcy浓度进行比较;根据Hachinski缺血指数量表评分将老年痴呆分为阿尔茨海默病(Alzheimer’s disease,AD),混合性痴呆(mixed dementia,MD),血管性痴呆(vascular dementia,VD);根据简易精神状态检查量表(Mini-Mental State Examination,MMSE)评分划分痴呆患者严重程度,分为轻度、中度、重度。结果:AD、MD、VD组血浆Hcy水平均显著高于对照组(P<0.01);不同程度痴呆患者血浆Hcy水平有显著性差异(P<0.05),血浆Hcy浓度越高,认知功能损害的程度越重。结论:高Hcy血症可能是老年期痴呆发病的一个重要危险因素,且认知功能减退的程度与血浆同型半胱氨酸浓度呈正相关。     

Alzheimer's dementia: current data review

The review focuses on current data on Alzhemier's dementia, a clinical syndrom characterised with acquired deterioration of cognitive functioning and emotional capacities, which impaires everyday activity and quality of life. Alzheimer's dementia is the most common type of dementia in clinical surveys. The diagnosis of Alzheimer's dementia is primarily based on symptoms and signs and memory impairment is clinically most significant. Cholinesterase inhibitors -donepezil, rivastigmine and galantamine are considered to be the first line pharmacotherapy for mild to moderate Alzheimer's disease. Currently, no effective pharmacologic interventions have been researched enough to support their use in prevention of Alzheimer's dementia. Studies suggest that healthy lifestyle, ongoing education, regular physical activity, and cholesterol control, play a role in prevention of Alzheimer's dementia.     

Validering van de Seven Minute Screen voor gebruik in de geheugenpolikliniek

Cognitive tests play a crucial part in the assessment of dementia. In 1998 the Seven Minute Screen was developed by Solomon and colleagues. The test was originally designed to distinguish between Alzheimer’s disease (AD) and normal ageing, and research showed that the instrument is highly sensitive to AD. Subsequent research also proved the diagnostic accuracy of the Seven Minute Screen in the detection of other common types of dementia, such as vascular dementia, frontotemporal dementia and dementia with Lewy bodies. This article reports new research on the predictive validity of the Seven Minute Screen using 289 cognitively intact subjects, 175 patients with MCI and 563 patients with dementia in the setting of a memory clinic. In addition, a comparison is made with the Mini Mental State Examination (MMSE). The study demonstrates that the Seven Minute Screen is a valuable screening instrument for all common types of dementia, and it has added value to the MMSE. The sensitivity for dementia is 96?% and the specificity 93?%, in comparison to 69 and 98?% for the MMSE (<?24). The sensitivity for the various types of dementia is consistently high, ranging from 92?% for a subcortical dementia to 97?% for AD. The Seven Minute Screen requires little training, and combines a short administration time with a high diagnostic accuracy. This makes the Seven Minute Screen useful for application in memory clinics.     

Peripheral ethanolamine plasmalogen deficiency: a logical causative factor in Alzheimer's disease and dementia

Although dementia of the Alzheimer's type (DAT) is the most common form of dementia, the severity of dementia is only weakly correlated with DAT pathology. In contrast, postmortem measurements of cholinergic function and membrane ethanolamine plasmalogen (PlsEtn) content in the cortex and hippocampus correlate with the severity of dementia in DAT. Currently, the largest risk factor for DAT is age. Because the synthesis of PlsEtn occurs via a single nonredundant peroxisomal pathway that has been shown to decrease with age and PlsEtn is decreased in the DAT brain, we investigated potential relationships between serum PlsEtn levels, dementia severity, and DAT pathology. In total, serum PlsEtn levels were measured in five independent population collections comprising >400 clinically demented and >350 nondemented subjects. Circulating PlsEtn levels were observed to be significantly decreased in serum from clinically and pathologically diagnosed DAT subjects at all stages of dementia, and the severity of this decrease correlated with the severity of dementia. Furthermore, a linear regression model predicted that serum PlsEtn levels decrease years before clinical symptoms. The putative roles that PlsEtn biochemistry play in the etiology of cholinergic degeneration, amyloid accumulation, and dementia are discussed.     

Joint Modeling for Cognitive Trajectory and Risk of Dementia in the Presence of Death

Summary .  Dementia is characterized by accelerated cognitive decline before and after diagnosis as compared to normal aging. It has been known that cognitive impairment occurs long before the diagnosis of dementia. For individuals who develop dementia, it is important to determine the time when the rate of cognitive decline begins to accelerate and the subsequent gap time to dementia diagnosis. For normal aging individuals, it is also useful to understand the trajectory of cognitive function until their death. A Bayesian change-point model is proposed to fit the trajectory of cognitive function for individuals who develop dementia. In real life, people in older ages are subject to two competing risks, e.g., dementia and dementia-free death. Because the majority of people do not develop dementia, a mixture model is used for survival data with competing risks, which consists of dementia onset time after the change point of cognitive function decline for demented individuals and death time for nondemented individuals. The cognitive trajectories and the survival process are modeled jointly and the parameters are estimated using the Markov chain Monte Carlo method. Using data from the Honolulu Asia Aging Study, we show the trajectories of cognitive function and the effect of education, apolipoprotein E 4 genotype, and hypertension on cognitive decline and the risk of dementia.     

The final phase of dementia in a group of nursing home patients: prevalence and characteristics

There is scant literature about patients in the final phase of dementia. Uniform terminology and operational definition of the final phase of dementia is lacking. Furthermore, it is difficult to monitor these patients because existing assessment scales face bottom- or ceiling effects in this population. The aim of this study was to assess the prevalence and the characteristics of patients in the final phase of dementia in a group of 210 Dutch nursing home patients with dementia. Stage 7 of the Global Deterioration Scale of Reisberg et al. was used to operationally define the final phase of dementia. All patients were scored on a self-constructed assessment scale. Furthermore, treatment aspects and advance directives were registered.     

Valoración funcional en la demencia grave

Severe dementia is currently one of the main causes of dependence and is defined as cognitive impairment that interferes with the performance of basic activities of daily living. However, in clinical practice severe dementia is difficult to define.Assessment of the ability to perform activities of daily living is a key factor in patients with severe dementia, since functional impairment is a defining feature. Assessment allows an accurate prognosis to be made and a care plan to be established, as well as the effectiveness of the intervention to be evaluated, when necessary.Functional assessment in dementia is complex, since functional status is the expression of multiple interactions, especially in geriatric patients. Functional status is measured by functional scales. In severe dementia, these scales must evaluate basic activities of daily living in the different types of dementia with high sensitivity to changes and strong discriminatory capacity. They should also be culturally adapted and validated in the community and institutional settings. Consensus should be established on the use of these instruments to allow them to be standardized and their results to be compared.     

Características Neuropsicológicas y Aproximación Diagnóstica a la Demencia Parkinson y a la Demencia por Cuerpos de Lewy

When approaching the neurophysiological characteristics and diagnostic approach to Parkinson's disease dementia (PDD) and Lewy body dementia (LBD), the first idea that comes to mind is that both types of dementia fall within the group of subcortical dementias, with the practical implications that this observation entails. We should therefore leave our knowledge of Alzheimer's dementia and other cortical dementias to one side as, in most cases, these forms of dementia do not correspond clinically or diagnostically to subcortical dementias. Therefore, the clinical and therapeutic approach of PDD and LBD differs from that of cortical dementias in form, if not in essence.     

Neuropsychological characteristics and diagnostic approach to Parkinsońs disease dementia and Lewy body dementia

When approaching the neurophysiological characteristics and diagnostic approach to Parkinson's disease dementia (PDD) and Lewy body dementia (LBD), the first idea that comes to mind is that both types of dementia fall within the group of subcortical dementias, with the practical implications that this observation entails. We should therefore leave our knowledge of Alzheimer's dementia and other cortical dementias to one side as, in most cases, these forms of dementia do not correspond clinically or diagnostically to subcortical dementias. Therefore, the clinical and therapeutic approach of PDD and LBD differs from that of cortical dementias in form, if not in essence.     

The diagnosis of dementia.

The diagnosis of dementia in the elderly has important personal and social consequences, and a small proportion of cases initially diagnosed may be reversible. An understanding of the operating characteristics and cost-effectiveness of clinical signs and symptoms and of laboratory investigations in the diagnosis of dementia is needed to diagnose accurately yet contain costs. Using published criteria, we critically appraised the current scientific literature on the diagnosis of dementia. The articles that essentially satisfied our criteria suggested that duration and severity of dementia best predicted reversibility and the need for computed tomography of the head. A decision rule may be used to select among a number of investigations now advocated as routine in diagnosing dementia, with little or no risk of missing clinically significant diagnoses and with appreciable cost savings. The reversibility of dementia may not be as major an issue as previously believed, since most instances may be early, atypical presentations of Alzheimer-type dementia.     

Dementia,the fate of brain? Neuropathological point of viewLe destin du cerveau ? Un point de vue neuropathologique sur les démences.

The prevalence of dementia dramatically increases during ageing, and this puts a serious strain on the optimism brought by the continuous increase in life expectancy observed in most industrialised countries. Diseases that produce dementia are numerous, and the cognitive deficit results from lesions of various regions and from different mechanisms. This modulates the possible prediction, prevention and cure of dementia. Emphasis is put on the necessity of, and prerequisite for, efficient research in the field of dementia. Three paradigmatic dementing disorders are reviewed. Subacute spongiform encephalopathies (prion diseases) constitute a biological enigma and a public health concern. In Alzheimer's disease and vascular or mixed dementia, the clinical diagnosis is still imperfect, and this hinders research. Distinguishing and accurately identifying the various types of dementia is essential for understanding their mechanism and for developing efficient therapeutic strategies, preventive and curative. For such objectives, the study of human brain tissue will remain mandatory until non-invasive markers and additional models are available. Ethical reasons banish the use of cerebral biopsy and favour the promotion of autopsy.     

不同部位梗死后痴呆的脑电图表现差异分析

目的:探讨不同部位脑梗死导致血管性痴呆的脑电图表现差异,为血管性痴呆的诊断分类提供客观依据。方法:80例诊断血管性痴呆的患者根据影像学表现分为多灶梗死后痴呆和关键部位梗死后痴呆。入选患者均于饱餐后2小时给予常规18导脑电图检查,记录时间为30分钟以上。结果:1多灶梗死后痴呆多表现为α节律减慢,6-8Hz为主;波幅低,以20-25Uv为主,α波频率调节差、节律不规则。低波幅θ波出现者27例,占71.1%,出现于各导联,出现δ波者17例,占44.7%。2关键部位梗死后痴呆的患者中,正常为6例,占13%。异常者39例,占87%。EEG改变主要表现为α指数减少,节律以7-9Hz为主的患者28例,占71.8%。低波幅θ波出现者17例,以前额为主,占43.6%。39例患者未出现δ波。结论:不同部位梗死后血管性痴呆的脑电图表现不尽相同,可以为血管性痴呆的分类诊断提供客观依据。     

Life- and person-centred help in Mecklenburg-Western Pomerania, Germany (DelpHi): study protocol for a randomised controlled trial

ABSTRACT: BACKGROUND: The provision of appropriate medical and nursing care for people with dementia is a major challenge for the healthcare system in Germany. New models of healthcare provision need to be developed, tested and implemented on the population level. Trials in which collaborative care for dementia in the primary care setting were studied have demonstrated its effectiveness. These studies have been conducted in different healthcare systems, however, so it is unclear whether these results extend to the specific context of the German healthcare system. The objective of this population-based intervention trial in the primary care setting is to test the efficacy and efficiency of implementing a subsidiary support system on a population level for persons with dementia who live at home. Methods and study design The study was designed to assemble a general physician-based epidemiological cohort of people above the age of 70 who live at home (DelpHi cohort). These people are screened for eligibility to participate in a trial of dementia care management (DelpHi trial). The trial is a cluster-randomised, controlled intervention trial with two arms (intervention and control) designed to test the efficacy and efficiency of implementing a subsidiary support system for persons with dementia who live at home. This subsidiary support system is initiated and coordinated by a dementia care manager: a nurse with dementia-specific qualifications who delivers the intervention according to a systematic, detailed protocol. The primary outcome is quality of life and healthcare for patients with dementia and their caregivers. This is a multidimensional outcome with a focus on four dimensions: (1) quality of life, (2) caregiver burden, (3) behavioural and psychological symptoms of dementia and (4) pharmacotherapy with an antidementia drug and prevention or suspension of potentially inappropriate medication. Secondary outcomes include the assessment of dementia syndromes, activities of daily living, social support health status, utilisation of health care resources and medication. DISCUSSION: The results will provide evidence for specific needs in ambulatory care for persons with dementia and will show effective ways to meet those needs. Qualification requirements will be evaluated, and the results will help to modify existing guidelines and treatment paths. Trial registration NCT01401582.     

Problemen en wensen van mantelzorgers van mensen met dementie: een vergelijking tussen de beginfase en latere fasen in het ziekteproces

This paper investigates whether informal caregivers of persons who have had symptoms of dementia for less than a year, differ from informal caregivers of persons in subsequent stages of dementia. Differences will be investigated in (a) problems experienced in the provision of informal care, (b) the use of ambulatory types of professional support, and (c) the need for additional professional support. Results are based on a survey among 1494 Dutch informal caregivers. Almost all informal caregivers experience problems in caring for a person with dementia, irrespective of the stage of the illness process. Their main problems concern dealing with changes in the behaviour of the person with dementia and dreading the person's admission to a nursing home. Informal caregivers of persons who have had symptoms of dementia for a longer period of time (> 1 year) also experience limitations in their social network. Most persons with dementia receive some kind of professional support. Still, the majority of informal caregivers indicate a need for additional professional support, mainly concerning advice and information. Limiting the available support options for persons with initial symptoms of dementia and their informal caregivers is therefore undesirable. Considering the need for additional support in the initial stage of dementia as well as in subsequent stages, persons with dementia and their informal caregivers should be supported during the entire illness process.     

Random change point model for joint modeling of cognitive decline and dementia

We propose a joint model for cognitive decline and risk of dementia to describe the pre-diagnosis phase of dementia. We aim to estimate the time when the cognitive evolution of subjects in the pre-dementia phase becomes distinguishable from normal evolution and to study whether the shape of cognitive decline depends on educational level. The model combines a piecewise polynomial mixed model with a random change point for the evolution of the cognitive test and a log-normal model depending on the random change point for the time to dementia. Parameters are estimated by maximum likelihood using a Newton-Raphson-like algorithm. The expected cognitive evolution given age to dementia is then derived and the marginal distribution of dementia is estimated to check the log-normal assumption.     

Have Quality and Outcomes Framework Depression Indicators changed referrals from primary care to a dedicated memory clinic?

The proportion of patients referred from primary care to dedicated dementia clinics who receive a final diagnosis of dementia is low. Many of these non-demented patients may have depressive disorders, since depression is the most common differential diagnosis of dementia. The UK general practitioner (GP) General Medical Services contract, introduced in April 2006, included a Quality and Outcomes Framework (QOF) with indicators related to depression. We investigated whether introduction of the QOF Depression Indicators changed the pattern of referrals from primary care to a dedicated dementia clinic. The results indicated that the null hypothesis could not be rejected.     

Neurochemical dementia diagnostics: State of the art and research perspectives

The aim of this review is to present current state of the art on the field of routine neurochemical dementia diagnostics (NDD) with a focus on cerebrospinal fluid (CSF) biomarkers: amyloid beta peptides, tau protein, and its phosphorylated form (pTau). After several years of experience, it is reasonably to postulate that CSF biomarkers analysis is an increasingly important tool within the early and differential diagnosis of dementia syndromes. Actual research activities are briefly discussed, too, including: (i) possibilities and limitations of the diagnosis of incipient Alzheimer's disease in preclinical stages (e.g., mild cognitive impairment), (ii) the role of multiplexing technologies in dementia biomarkers research, (iii) the role of biomarkers in differential diagnosis of dementia syndromes, (iv) approaches to improve analytical performance of available methods, and (v) research activities to identify dementia biomarkers in blood.     

A role for NOX NADPH oxidases in Alzheimer's disease and other types of dementia?

Because of population ageing, dementias are likely to become a major scourge of the 21st century. Causes of dementia include Alzheimer's disease, cerebrovascular disease, and lesser known entities such as frontotemporal dementia or dementia with Lewy bodies. Neuroinflammation is likely to play an important role in the pathogenesis of dementia by the killing of neurons through inflammatory mechanisms. Such a role of neuroinflammation is well documented for Alzheimer's disease, and it is likely to play a role in other types of dementia as well. Reactive oxygen species (ROS) play a key role in inflammatory tissue destruction. The phagocyte NADPH oxidase NOX2 is the best studied ROS-generating system. In the central nervous system, it is expressed in microglia and--to a lesser extent--in neurons. Indeed, there is emerging experimental evidence for a role of NOX2 in Alzheimer's and cerebrovascular disease. Recently, six novel ROS-generating NADPH oxidases with homology to NOX2 have been discovered. Several of them are also expressed in the central nervous system. In this article, we hypothesize a role of NOX-type NADPH oxidases in inflammatory neuronal loss. We review presently available evidence and suggest that NOX-type NADPH oxidases may become promising pharmacological targets for the treatment and prevention of dementia.     

Multiple imputation for estimating the risk of developing dementia and its impact on survival

Dementia, Alzheimer's disease in particular, is one of the major causes of disability and decreased quality of life among the elderly and a leading obstacle to successful aging. Given the profound impact on public health, much research has focused on the age-specific risk of developing dementia and the impact on survival. Early work has discussed various methods of estimating age-specific incidence of dementia, among which the illness-death model is popular for modeling disease progression. In this article we use multiple imputation to fit multi-state models for survival data with interval censoring and left truncation. This approach allows semi-Markov models in which survival after dementia depends on onset age. Such models can be used to estimate the cumulative risk of developing dementia in the presence of the competing risk of dementia-free death. Simulations are carried out to examine the performance of the proposed method. Data from the Honolulu Asia Aging Study are analyzed to estimate the age-specific and cumulative risks of dementia and to examine the effect of major risk factors on dementia onset and death.