IMPORTANCE: Worldwide, 47 million people live with dementia and, by 2050, the number is expected to increase to 131 million. OBSERVATIONS: Dementia is an acquired loss of cognition in multiple ...cognitive domains sufficiently severe to affect social or occupational function. In the United States, Alzheimer disease, one cause of dementia, affects 5.8 million people. Dementia is commonly associated with more than 1 neuropathology, usually Alzheimer disease with cerebrovascular pathology. Diagnosing dementia requires a history evaluating for cognitive decline and impairment in daily activities, with corroboration from a close friend or family member, in addition to a thorough mental status examination by a clinician to delineate impairments in memory, language, attention, visuospatial cognition such as spatial orientation, executive function, and mood. Brief cognitive impairment screening questionnaires can assist in initiating and organizing the cognitive assessment. However, if the assessment is inconclusive (eg, symptoms present, but normal examination findings), neuropsychological testing can help determine whether dementia is present. Physical examination may help identify the etiology of dementia. For example, focal neurologic abnormalities suggest stroke. Brain neuroimaging may demonstrate structural changes including, but not limited to, focal atrophy, infarcts, and tumor, that may not be identified on physical examination. Additional evaluation with cerebrospinal fluid assays or genetic testing may be considered in atypical dementia cases, such as age of onset younger than 65 years, rapid symptom onset, and/or impairment in multiple cognitive domains but not episodic memory. For treatment, patients may benefit from nonpharmacologic approaches, including cognitively engaging activities such as reading, physical exercise such as walking, and socialization such as family gatherings. Pharmacologic approaches can provide modest symptomatic relief. For Alzheimer disease, this includes an acetylcholinesterase inhibitor such as donepezil for mild to severe dementia, and memantine (used alone or as an add-on therapy) for moderate to severe dementia. Rivastigmine can be used to treat symptomatic Parkinson disease dementia. CONCLUSIONS AND RELEVANCE: Alzheimer disease currently affects 5.8 million persons in the United States and is a common cause of dementia, which is usually accompanied by other neuropathology, often cerebrovascular disease such as brain infarcts. Causes of dementia can be diagnosed by medical history, cognitive and physical examination, laboratory testing, and brain imaging. Management should include both nonpharmacologic and pharmacologic approaches, although efficacy of available treatments remains limited.
Summary Background Few data on the pathology of cerebral vessel disease, dementia, and cognition are available. We examined the association of cerebral atherosclerosis and arteriolosclerosis ...neuropathology with probable and possible Alzheimer's disease dementia and cognitive function. Methods This cross-sectional study included men and women aged 65 years or older who had yearly clinical assessments and had agreed to brain autopsy at the time of death, as part of one of two cohort studies of ageing (The Religious Orders Study and the Rush Memory and Aging Project). Individuals without dementia or with Alzheimer's disease dementia, and with complete neuropathological data, are included in our analyses. We used neuropsychological data proximate to death to create summary measures of global cognition and cognitive domains. Clinical data recorded between 1994 and 2015 were used to determine presence of Alzheimer's disease dementia. Systematic neuropathological assessments documented the severity of cerebral large vessel (atherosclerosis) and small vessel (arteriolosclerosis) disease. By use of regression analyses adjusted for demographics, gross and microscopic infarcts, and Alzheimer's disease pathology, we examined associations of vessel disease severity (mild, moderate, and severe) with odds of probable and possible Alzheimer's disease dementia and cognitive function. Findings Study enrolment began in January, 1994, and two cohort studies are ongoing. 1143 individuals were included in our analyses (median age at death 88·8 years; 478 42% with Alzheimer's disease dementia). Moderate-to-severe atherosclerosis was present in 445 (39%) individuals, and arteriolosclerosis in 401 (35%) individuals. Each level increase in the severity of atherosclerosis or arteriolosclerosis was associated with significantly higher odds of Alzheimer's disease dementia (odds ratio OR for atherosclerosis 1·33, 95% CI 1·11–1·58; OR for arteriolosclerosis 1·20, 1·04–1·40). Atherosclerosis was associated with lower scores for global cognition (estimate −0·10 SE 0·04, p=0·0096) and four cognitive domains (episodic memory −0·10 0·04, p=0·017; semantic memory −0·11 0·05, p=0·018; perceptual speed −0·14 0·04, p=0·00080; and visuospatial abilities −0·13 0·04, p=0·0080), but not working memory (−0·05 0·04, p=0·21). Arteriolosclerosis was associated with lower scores for global cognition (estimate −0·10 0·03, p=0·0015) and four domains (episodic memory −0·12 0·04, p=0·00090; semantic memory −0·10 0·04, p=0·013; working memory −0·07 0·03, p=0·045; perceptual speed −0·12 0·04, p=0·0012), and a non-significant association was noted for visuospatial abilities (−0·07 0·03, p=0·052). Findings were unchanged in analyses controlling for the presence of APOE ε4 allele or vascular risk factors. Interpretation Cerebral atherosclerosis and arteriolosclerosis are associated with Alzheimer's disease dementia, and are also associated with low scores in most cognitive domains. Cerebral vessel pathology might be an under-recognised risk factor for Alzheimer's disease dementia. Funding US National Institutes of Health.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The genetics of complex disease produce alterations in the molecular interactions of cellular pathways whose collective effect may become clear through the organized structure of molecular networks. ...To characterize molecular systems associated with late-onset Alzheimer’s disease (LOAD), we constructed gene-regulatory networks in 1,647 postmortem brain tissues from LOAD patients and nondemented subjects, and we demonstrate that LOAD reconfigures specific portions of the molecular interaction structure. Through an integrative network-based approach, we rank-ordered these network structures for relevance to LOAD pathology, highlighting an immune- and microglia-specific module that is dominated by genes involved in pathogen phagocytosis, contains TYROBP as a key regulator, and is upregulated in LOAD. Mouse microglia cells overexpressing intact or truncated TYROBP revealed expression changes that significantly overlapped the human brain TYROBP network. Thus the causal network structure is a useful predictor of response to gene perturbations and presents a framework to test models of disease mechanisms underlying LOAD.
Display omitted
•Systems approach to LOAD based on large-scale human brain-tissue sampling•Molecular networks show strong remodeling effect in LOAD brains•Integrative network-based analysis implicates the immune/microglia network in LOAD•TYROBP implicated as key causal regulator within the immune/microglia module
An integrated systems approach leverages transcriptome data from postmortem brains of late-onset Alzheimer’s disease patients to identify key nodes that drive dysregulated or rewired networks in the disease state.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Religious Orders Study is a longitudinal clinical-pathologic cohort study of aging and Alzheimer's disease (AD). In this manuscript, we summarize the study methods including the study design and ...describe the clinical evaluation, assessment of risk factors, collection of ante-mortem biological specimens, brain autopsy and collection of selected postmortem data.
(1) review the relation of neuropathologic indices to clinical diagnoses and cognition proximate to death; (2) examine the relation of risk factors to clinical outcomes; (3) examine the relation of risk factors to measures of neuropathology; and (4) summarize additional study findings. We then discuss and contextualize the study findings.
As the US elderly population continues to expand rapidly, Alzheimer's disease poses a major and increasing public health challenge, and older African Americans may be disproportionately burdened by ...the disease. Although African Americans were generally underincluded in previous research studies, new and growing evidence suggests that they may be at increased risk of the disease and that they differ from the non-Hispanic white population in risk factors and disease manifestation. This article offers an overview of the challenges of Alzheimer's disease in African Americans, including diagnosis issues, disparities in risk factors and clinical presentation of disease, and community-based recommendations to enhance research with this population.
The Memory and Aging Project is a longitudinal, epidemiologic clinical-pathologic cohort study of common chronic conditions of aging with an emphasis on decline in cognitive and motor function and ...risk of Alzheimer's disease (AD). In this manuscript, we first summarize the study design and methods. Then, we present data on: (1) the relation of motor function to cognition, disability, and death; (2) the relation of risk factors to cognitive and motor outcomes, disability and death; (3) the relation of neuropathologic indices to cognitive outcomes; (4) the relation of risk factors to neuropathologic indices; and (5) additional study findings. The findings are discussed and contextualized.
Alzheimer’s dementia is significantly more common in women than in men. However, few pathological studies have addressed sex difference in Alzheimer’s disease (AD) and other brain pathologies. We ...leveraged postmortem data from 1453 persons who participated in one of two longitudinal community-based studies of older adults, the Religious Orders Study and the Rush Memory and Aging Project. Postmortem examination identified AD pathologies, neocortical Lewy bodies, DNA-binding protein 43 (TDP-43), hippocampal sclerosis, gross and micro infarcts, atherosclerosis, arteriolosclerosis, and cerebral amyloid angiopathy. Linear and logistic regressions examined the association of sex with each of the pathologic measures. Two-thirds of subjects were women (
n
= 971; 67%), with a mean age at death of 89.8 (SD = 6.6) years in women and 87.3 (SD = 6.6) in men. Adjusted for age and education, women had higher levels on a global measure of AD pathology (estimate = 0.102, SE = 0.022,
p
< 0.001), and tau tangle density in particular (estimate = 0.334, SE = 0.074,
p
< 0.001), and there was a borderline difference between women and men in amyloid-β load (estimate = 0.124, SE = 0.065,
p
= 0.056). In addition, compared to men, women were more likely to have more severe arteriolosclerosis (OR = 1.28, 95% CI:1.04–1.58,
p
= 0.018), and less likely to have gross infarcts (OR = 0.78, 95% CI:0.61–0.98,
p
= 0.037), although the association with gross infarct was attenuated after controlling for vascular risk factors. These data help elucidate the neuropathologic footprint of sex difference in AD and other common brain pathologies of aging.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Clinical studies indicate that Alzheimer's disease (AD) disproportionately affects women in both disease prevalence and rate of symptom progression, but the mechanisms underlying this sexual ...divergence are unknown. Although some have suggested this difference in risk is a reflection of the known differences in longevity between men and women, mounting clinical and preclinical evidence supports women also having intrinsic susceptibilities toward the disease. Although a number of potential risk factors have been hypothesized to mediate these differences, none have been definitively verified. In this review, we first summarize the epidemiologic studies of prevalence and incidence of AD among the sexes. Next, we discuss the most likely risk factors to date that interact with biological sex, including (1) genetic factors, (2) sex hormones (3) deviations in brain structure, (4) inflammation and microglia, and (5) and psychosocial stress responses. Overall, though differences in life span are likely to account for part of the divide between the sexes in AD prevalence, the abundance of preclinical and clinical evidence presented here suggests an increase in intrinsic AD risk for women. Therefore, future studies focusing on the underlying biological mechanisms for this phenomenon are needed to better understand AD pathogenesis in both sexes, with the eventual goal of sex-specific prevention and treatment strategies.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or ...special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.
Full text
Available for:
BFBNIB, NUK, PNG, UL, UM, UPUK
PDF
