J Alzheimers Dis
January 2022
Background:: Metals, silicon, and homocysteine are linked to Alzheimer’s disease. B vitamin therapy lowers homocysteine and slows brain atrophy and cognitive decline in mild cognitive impairment (MCI).
Objective:: Examine metals and silicon as predictors of cognition/brain atrophy in MCI, their interaction with homocysteine and cysteine, and how B vitamins affect these relationships.
Background: Identification of modifiable risk factors that affect cognitive decline is important for the development of preventive and treatment strategies. Status of paraoxonase 1 (PON1), a high-density lipoprotein-associated enzyme, may play a role in the development of neurological diseases, including Alzheimer's disease.
Objective: We tested a hypothesis that PON1 status predicts cognition in individuals with mild cognitive impairment (MCI).
The COVID-19 pandemic is imposing a profound negative impact on the health and wellbeing of societies and individuals, worldwide. One concern is the effect of social isolation as a result of social distancing on the mental health of vulnerable populations, including older people. Within six weeks of lockdown, we initiated the CHARIOT COVID-19 Rapid Response Study, a bespoke survey of cognitively healthy older people living in London, to investigate the impact of COVID-19 and associated social isolation on mental and physical wellbeing.
View Article and Find Full Text PDFJ Clin Exp Neuropsychol
October 2020
Alzheimer's disease (AD) is the most common form of dementia, impacting global cognitive performance, including episodic memory. Semantic clustering is a learning strategy involving grouping words of similar meaning and can improve episodic memory performance, e.g.
View Article and Find Full Text PDFThe 2018 National Institute on Aging and the Alzheimer's Association (NIA-AA) research framework recently redefined Alzheimer's disease (AD) as a biological construct, based on in vivo biomarkers reflecting key neuropathologic features. Combinations of normal/abnormal levels of three biomarker categories, based on single thresholds, form the AD signature profile that defines the biological disease state as a continuum, independent of clinical symptomatology. While single thresholds may be useful in defining the biological signature profile, we provide evidence that their use in studies with cognitive outcomes merits further consideration.
View Article and Find Full Text PDFObjective: We explored the prevalence of HIV infection in older rural South Africans and its associations, as well as the point prevalence of dementia and its associations with HIV and aging.
Design: We utilized a cross-sectional analytic design.
Methods: Using the brief Community Screening Instrument for Dementia together with a rapid HIV test, we conducted a home-based screening survey among 1150 older South Africans.
Background: Dementia is a growing concern for low- and middle-income countries where longevity is increasing and service provision is poor. Global prevalence estimates vary from 2% to 8.5% for those aged 60 years and older.
View Article and Find Full Text PDFA randomized trial (VITACOG) in people with mild cognitive impairment (MCI) found that B vitamin treatment to lower homocysteine slowed the rate of cognitive and clinical decline. We have used data from this trial to see whether baseline omega-3 fatty acid status interacts with the effects of B vitamin treatment. 266 participants with MCI aged ≥70 years were randomized to B vitamins (folic acid, vitamins B6 and B12) or placebo for 2 years.
View Article and Find Full Text PDFMixed vascular and Alzheimer-type dementia and pure Alzheimer's disease are both associated with changes in spoken language. These changes have, however, seldom been subjected to systematic comparison. In the present study, we analyzed language samples obtained during the course of a longitudinal clinical study from patients in whom one or other pathology was verified at post mortem.
View Article and Find Full Text PDFNeurobiol Aging
September 2014
Few B-vitamin trials to lower homocysteine (Hcy) have reported evidence of beneficial effects on cognition in older adults with cognitive impairment or Alzheimer's disease. This article reviews the role of Hcy in cognitive decline. It also considers some reasons why meta-analyses have failed to find effects of B-vitamin treatment.
View Article and Find Full Text PDFRisk of developing Alzheimer's disease is increased by older age, genetic factors, and several medical risk factors. Studies have also suggested that dietary and lifestyle factors may influence risk, raising the possibility that preventive strategies may be effective. This body of research is incomplete.
View Article and Find Full Text PDFThis review is an output of the International Life Sciences Institute (ILSI) Europe Marker Initiative, which aims to identify evidence-based criteria for selecting adequate measures of nutrient effects on health through comprehensive literature review. Experts in cognitive and nutrition sciences examined the applicability of these proposed criteria to the field of cognition with respect to the various cognitive domains usually assessed to reflect brain or neurological function. This review covers cognitive domains important in the assessment of neuronal integrity and function, commonly used tests and their state of validation, and the application of the measures to studies of nutrition and nutritional intervention trials.
View Article and Find Full Text PDFAlthough an insidious history of episodic memory difficulty is a typical presenting symptom of Alzheimer's disease, detailed neuropsychological profiling frequently demonstrates deficits in other cognitive domains, including language. Previous studies from our group have shown that language changes may be reflected in connected speech production in the earliest stages of typical Alzheimer's disease. The aim of the present study was to identify features of connected speech that could be used to examine longitudinal profiles of impairment in Alzheimer's disease.
View Article and Find Full Text PDFChanges in the hippocampal system have been proposed as a possible marker of incipient Alzheimer's disease (AD) at the mild cognitive impairment (MCI) stage. The Placing Test (TPT) evaluates the efficiency of the hippocampal system by measuring the ability to remember associations between images and their locations. Our aim was to validate a novel paper-and-pencil (PnP) version of TPT featuring people's faces in color (versus the traditional test carried out with black-and-white images) and a computerized Placing test with categories of objects, faces, and animals (versus a version featuring the categories of objects, faces, and shapes).
View Article and Find Full Text PDFBackground: Subtle cognitive changes have been described that may predate the onset of clinically recognizable Alzheimer's disease (AD) and may reflect pathological changes in the brain that are detectable up to 10 years before the onset of AD. Early screening for cognitive status can have benefits in terms of early management and prevention strategies for cognitive decline.
Method: A novel computerized cognitive screening tool, the Cognitive Function Test (CFT), was compared with established paper tests of episodic memory, executive function and processing speed, domains previously shown to be predictive of AD, with 50 normal participants, Mini Mental State Examination ≥24, mean age 58.
Proc Natl Acad Sci U S A
June 2013
Is it possible to prevent atrophy of key brain regions related to cognitive decline and Alzheimer's disease (AD)? One approach is to modify nongenetic risk factors, for instance by lowering elevated plasma homocysteine using B vitamins. In an initial, randomized controlled study on elderly subjects with increased dementia risk (mild cognitive impairment according to 2004 Petersen criteria), we showed that high-dose B-vitamin treatment (folic acid 0.8 mg, vitamin B6 20 mg, vitamin B12 0.
View Article and Find Full Text PDFObjective: To establish whether, in a cohort with normal cognition, severity of depressive symptoms at baseline was related to the time taken for conversion to mild cognitive impairment (MCI) and whether this interacted with other potential risk factors, including APOE ε4 status and demographic and cognitive variables.
Methods: In a population-based cohort study, 126 cognitively normal subjects were assessed for depressive symptoms at baseline using the Geriatric Depression Scale (GDS) and were then followed over 20 years with regular cognitive assessments. The interval-censored accelerated failure time model was used to establish whether GDS and other factors, including APOE ε4 status, predicted the median time to development of MCI.
Neuronal glucose uptake was thought to be independent of insulin, being facilitated by glucose transporters GLUT1 and GLUT3, which do not require insulin signaling. However, it is now known that components of the insulin-mediated glucose uptake pathway, including neuronal insulin synthesis and the insulin-dependent glucose transporter GLUT4, are present in brain tissue, particularly in the hippocampus. There is considerable recent evidence that insulin signaling is crucial to optimal hippocampal function.
View Article and Find Full Text PDFObjective: The aim of the present study was to quantify the semantic content of connected speech produced by patients at a uniformly early stage of pathologically proven Alzheimer's disease (AD). A secondary aim was to establish whether semantic units were reduced globally, or whether there was a disproportionate reduction of specific classes of information.
Method: Discourse samples were obtained from 18 AD patients and 18 matched controls, all pathologically confirmed.
Objectives: to evaluate the relationship between neurocognitive speed (NCS) and frailty; to consider how this relationship is affected by how frailty is operationalised.
Design: secondary analysis of the baseline cohort of the Oxford Project To Investigate Memory and Aging (OPTIMA), a longitudinal observational cohort.
Subjects: of 388 participants who underwent a comprehensive intake assessment followed by an annual follow-up for at least 3 years, data on all measures were available on 164 people.
Impaired visuospatial associative memory may be one of the earliest changes predicting cognitive impairment and Alzheimer's disease. We explored the relationship between performance on a visuospatial associative memory task (the Placing Test) and brain structure and function in cognitively healthy older adults. First, we performed a voxel-based morphometry correlational analysis on structural magnetic resonance imaging (MRI) data from 144 healthy older adults with their scores on the Placing Test.
View Article and Find Full Text PDFJ Neurol Neurosurg Psychiatry
November 2012
Background: Primary progressive aphasia (PPA) is a clinical syndrome characterised by progressive decline in components of the language system. Recent evidence suggests that the logopenic/phonological (LPA) variant is a reliable in vivo marker of Alzheimer related pathology. The aim of this study was to determine if patients with clinically typical early stage Alzheimer's disease (AD) display a characteristic language disorder that resembles LPA, or if LPA is a clinical manifestation of an atypical form of AD.
View Article and Find Full Text PDFThe comparative ability of the Montreal Cognitive Assessment (MoCA) and MMSE to detect mild cognitive difficulties was investigated in 107 older adults. The sensitivity of the MoCA to detect cognitive impairment with a cutoff score of <26 was investigated, as compared to the MMSE across all scores, and at a cutoff of ≥27. Performance on MoCA subtests was compared at these MMSE cutoffs to determine profiles of early cognitive difficulties.
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